The Collaborative International Dictionary of English v.0.48:

Contact \Con"tact\ (k[o^]n"t[a^]kt), n. [L. contactus, fr.
   contingere, -tactum, to touch on all sides. See
   Contingent.]
   1. A close union or junction of bodies; a touching or
      meeting.
      [1913 Webster]

   2. (Geom.) The property of two curves, or surfaces, which
      meet, and at the point of meeting have a common direction.
      [1913 Webster]

   3. (Mining) The plane between two adjacent bodies of
      dissimilar rock. --Raymond.
      [1913 Webster]

   4. (Electricity) A metallic conducting component of an
      electrical device connected to a circuit within and so
      situated that it may form a conducting pathway to an
      external power source or device when contacted by another
      conductor; as, the contact on a standard light bulb has
      the shape of a screw for easy insertion into the socket.
      [PJC]

   5. A person who serves to commmunicate information to or from
      one group to another, whether formally or informally; as,
      a good Washington reporter has contacts in the White
      House.
      [PJC]

   Contact level, a delicate level so pivoted as to tilt when
      two parts of a measuring apparatus come into contact with
      each other; -- used in precise determinations of lengths
      and in the accurate graduation of instruments.
      [1913 Webster]

WordNet (r) 3.0 (2006):

contact
    n 1: close interaction; "they kept in daily contact"; "they
         claimed that they had been in contact with extraterrestrial
         beings"
    2: the act of touching physically; "her fingers came in contact
       with the light switch" [syn: contact, physical contact]
    3: the state or condition of touching or of being in immediate
       proximity; "litmus paper turns red on contact with an acid"
    4: the physical coming together of two or more things; "contact
       with the pier scraped paint from the hull" [syn: contact,
       impinging, striking]
    5: a person who is in a position to give you special assistance;
       "he used his business contacts to get an introduction to the
       governor" [syn: contact, middleman]
    6: a channel for communication between groups; "he provided a
       liaison with the guerrillas" [syn: liaison, link,
       contact, inter-group communication]
    7: (electronics) a junction where things (as two electrical
       conductors) touch or are in physical contact; "they forget to
       solder the contacts" [syn: contact, tangency]
    8: a communicative interaction; "the pilot made contact with the
       base"; "he got in touch with his colleagues" [syn: contact,
       touch]
    9: a thin curved glass or plastic lens designed to fit over the
       cornea in order to correct vision or to deliver medication
       [syn: contact, contact lens]
    v 1: be in or establish communication with; "Our advertisements
         reach millions"; "He never contacted his children after he
         emigrated to Australia" [syn: reach, get through, get
         hold of, contact]
    2: be in direct physical contact with; make contact; "The two
       buildings touch"; "Their hands touched"; "The wire must not
       contact the metal cover"; "The surfaces contact at this
       point" [syn: touch, adjoin, meet, contact]

Moby Thesaurus II by Grady Ward, 1.0:

153 Moby Thesaurus words for "contact":
   ESP, accord, acquaintance, answer, approach, arbitrator,
   assail the ear, association, attouchement, be heard, breath,
   broker, brush, brush by, caress, caress the ear, closeness,
   come in contact, commerce, communicate with, communication,
   communion, companionship, concord, congress, conjunction,
   connection, contiguity, contingence, conversation, converse,
   correspond, correspond with, correspondence, cutaneous sense,
   dealing, dealings, empathy, establish connection, exchange, feel,
   feeling, fellowship, fingertip caress, flick, friend,
   gain a hearing, get, get across, get hold of, get through to,
   get to, glance, go-between, graze, hand-mindedness, harmony, hit,
   impinge, impingement, impingence, in, information, interaction,
   interagent, interchange, intercommunication, intercommunion,
   intercourse, intermediary, intermediate, intermedium, internuncio,
   interplay, interpleader, interrogate, junction, kiss, lambency,
   lap, lick, light touch, linguistic intercourse,
   maintain connection, make advances, make an impression,
   make contact with, make oneself heard, make overtures, make up to,
   mediator, medium, message, middleman, nearness, negotiant,
   negotiator, nudge, oneness, osculate, osculation, phone,
   propinquity, proximity, question, raise, rapport, reach,
   reach the ear, register, relate to, relation, reply, reply to,
   respond to, response, ring up, rub, scrape, sense of touch, shave,
   sideswipe, skim, skirt, social intercourse, speak to, speak with,
   speaking, speech, speech circuit, speech situation, squeak by,
   stroke, sympathy, tactile sense, taction, talking, tangency, tap,
   telepathy, telephone, tentative contact, tentative poke, touch,
   touching, traffic, truck, two-way communication, understanding,
   union, unity, whisper, write to