The Collaborative International Dictionary of English v.0.48:

Associate \As*so"ci*ate\, a. [L. associatus, p. p.]
   1. Closely connected or joined with some other, as in
      interest, purpose, employment, or office; sharing
      responsibility or authority; as, an associate judge.
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            While I descend . . . to my associate powers.
                                                  --Milton.
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   2. Admitted to some, but not to all, rights and privileges;
      as, an associate member.
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   3. (Physiol.) Connected by habit or sympathy; as, associate
      motions, such as occur sympathetically, in consequence of
      preceding motions. --E. Darwin.
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The Collaborative International Dictionary of English v.0.48:

Associate \As*so"ci*ate\, v. t. [imp. & p. p. Associated; p.
   pr. & vb. n. Associating.] [L. associatus, p. p. of
   associare; ad + sociare to join or unite, socius companion.
   See Social.]
   1. To join with one, as a friend, companion, partner, or
      confederate; as, to associate others with us in business,
      or in an enterprise.
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   2. To join or connect; to combine in acting; as, particles of
      gold associated with other substances.
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   3. To connect or place together in thought.
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            He succeeded in associating his name inseparably
            with some names which will last as long as our
            language.                             --Macaulay.
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   4. To accompany; to keep company with. [Obs.]
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            Friends should associate friends in grief and woe.
                                                  --Shak.
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The Collaborative International Dictionary of English v.0.48:

Associate \As*so"ci*ate\, n.
   1. A companion; one frequently in company with another,
      implying intimacy or equality; a mate; a fellow.
      [1913 Webster]

   2. A partner in interest, as in business; or a confederate in
      a league.
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   3. One connected with an association or institution without
      the full rights or privileges of a regular member; as, an
      associate of the Royal Academy.
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   4. Anything closely or usually connected with another; an
      concomitant.
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            The one [idea] no sooner comes into the
            understanding, than its associate appears with it.
                                                  --Locke.
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   Syn: Companion; mate; fellow; friend; ally; partner;
        coadjutor; comrade; accomplice.
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The Collaborative International Dictionary of English v.0.48:

Associate \As*so"ci*ate\, v. i.
   1. To unite in company; to keep company, implying intimacy;
      as, congenial minds are disposed to associate.
      [1913 Webster]

   2. To unite in action, or to be affected by the action of a
      different part of the body. --E. Darwin.
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WordNet (r) 3.0 (2006):

associate
    adj 1: having partial rights and privileges or subordinate
           status; "an associate member"; "an associate professor"
    n 1: a person who joins with others in some activity or
         endeavor; "he had to consult his associate before
         continuing"
    2: a friend who is frequently in the company of another;
       "drinking companions"; "comrades in arms" [syn: companion,
       comrade, fellow, familiar, associate]
    3: a person with subordinate membership in a society,
       institution, or commercial enterprise; "associates in the law
       firm bill at a lower rate than do partners"
    4: any event that usually accompanies or is closely connected
       with another; "first was the lightning and then its
       thunderous associate"
    5: a degree granted by a two-year college on successful
       completion of the undergraduates course of studies [syn:
       associate degree, associate]
    v 1: make a logical or causal connection; "I cannot connect
         these two pieces of evidence in my mind"; "colligate these
         facts"; "I cannot relate these events at all" [syn:
         associate, tie in, relate, link, colligate, link
         up, connect] [ant: decouple, dissociate]
    2: keep company with; hang out with; "He associates with strange
       people"; "She affiliates with her colleagues" [syn:
       consort, associate, affiliate, assort]
    3: bring or come into association or action; "The churches
       consociated to fight their dissolution" [syn: consociate,
       associate]

Moby Thesaurus II by Grady Ward, 1.0:

406 Moby Thesaurus words for "associate":
   Greek, abettor, accessory, accompany, accomplice, accord, accouple,
   accumulate, ace, acquaintance, act in concert, act together,
   affiliate, affiliate with, affiliated, affiliation, agglutinate,
   agree, alliance, allied, ally, alter ego, amalgamate, amass, amigo,
   analogon, analogue, appearance, apply, articulate, assemble,
   assistant, assistant professor, associate, associate professor,
   associate with, associated, association, assort with, attend, axis,
   band, band together, be acquainted with, be friends, be in cahoots,
   be in league, be inseparable, bedfellow, bedmate, belonger, bind,
   blend, bloc, bond, bosom buddy, bracket, bridge, bridge over,
   brother, brother-in-arms, brotherhood, buddy, bunch, bunch up,
   bunkie, bunkmate, butty, cabal, cahoots, camarade, card-carrier,
   card-carrying member, cardholder, cement, cement a union,
   centralize, chain, chamberfellow, charter member, chum,
   chum together, chum with, circuit, clap together, classmate,
   clique, clique with, close copy, close match, club, club together,
   clubber, clubman, clubwoman, coact, coaction, coadunate, coalesce,
   coalition, cognate, cohort, coincide, collaborate, collaboration,
   collaborator, colleague, collect, collude, comate, combination,
   combine, come into, come together, committeeman, companion,
   company, compatriot, compeer, complement, comprise, comrade,
   concatenate, concert, concomitant, concord, concur, confederate,
   conference, confidant, confidante, confrere, congenator, congener,
   conglobulate, congress, conjoin, conjugate, conjunction, connect,
   connect with, connection, connive, connotation, consociate,
   consolidate, consort, consort with, conspire, conventioneer,
   conventioner, conventionist, conviviality, cooperate, cooperation,
   coordinate, copartner, copulate, correlate, correlative,
   correspond, correspondent, cotton to, counterpart, couple,
   couple with, cover, creep in, crony, do business with,
   draw a parallel, dues-paying member, embrace, emeritus, encompass,
   enlist, enlistee, enroll, enrollee, enter, equate, equivalent,
   faction, familiar, fantasy, federalize, federate, federation,
   fellow, fellow student, fellowship, flock together, fraternity,
   fraternity man, fraternize, fraternize with, friend, fuse, gaiety,
   gang, gang up, gather, get heads together, get into, get together,
   girl friend, glue, go along with, go in partners,
   go in partnership, go into, go partners, go with, gossip, guild,
   guildsman, hang around with, hang out with, hang together,
   happen together, harmonize, herd together, hint, hit it off,
   hobnob with, hold together, honorary member, hook up, hook up with,
   hookup, identify, illusion, image, implication, include, initiate,
   insider, instructor, interest, interrelate, intimate, join,
   join forces, join fortunes with, join in, join in fellowship,
   join together, join up, join up with, join with, joiner, joviality,
   keep company with, keep together, kindred spirit, knot, know,
   lay together, league, league together, league with, leaguer,
   lecturer, life member, like, likeness, link, loop, lump together,
   machine, make common cause, marry, marshal, mass, match, mate,
   member, merge, messmate, mingle, mingle with, mirage, mix,
   mix with, mobilize, near duplicate, obverse, old crony, one of us,
   order, organization, organize, overtone, pair, pair off, pal,
   pal up with, pal with, parallel, parallelize, pard, pardner,
   partner, partnership, pendant, picture, piece together, play ball,
   playfellow, playmate, pledge, professor, professor emeritus,
   pull together, put heads together, put together, reader,
   reciprocal, reciprocate, relate, relativize, retired professor,
   ring, roll into one, roommate, run in couples, run with,
   schoolfellow, schoolmate, second self, secondary, sect, see,
   shipmate, side partner, sidekick, sign on, sign up, similitude,
   simulacrum, sister, sneak in, sociability, society, socius,
   sodality, solder, sorority girl, sorority woman, sort with,
   soul mate, span, splice, stand together, stand up with,
   stick together, subsidiary, such, suchlike, suggestion,
   sympathizer, synchronize, synergize, take in, take out membership,
   take up membership, take up with, tally, tape, team up,
   team up with, team with, teammate, teamwork, the like of,
   the likes of, throw in together, throw in with, tie, tie in,
   tie in with, tie up, tie up with, tie-up, togetherness, tutor,
   twin, undertone, unify, union, unionize, unite, unite efforts,
   unite with, vision, visiting professor, wait on, wed, weld, wheel,
   wing, work together, workfellow, yoke, yokefellow, yokemate