The Collaborative International Dictionary of English v.0.48:

Intimacy \In"ti*ma*cy\, n.; pl. Intimacies. [From Intimate.]
   The state of being intimate; close familiarity or
   association; nearness in friendship.

   Syn: Acquaintance; familiarity; fellowship; friendship. See
        Acquaintance.
        [1913 Webster]

WordNet (r) 3.0 (2006):

intimacy
    n 1: close or warm friendship; "the absence of fences created a
         mysterious intimacy in which no one knew privacy" [syn:
         familiarity, intimacy, closeness]
    2: a usually secretive or illicit sexual relationship [syn:
       affair, affaire, intimacy, liaison, involvement,
       amour]
    3: a feeling of being intimate and belonging together; "their
       closeness grew as the night wore on" [syn: closeness,
       intimacy]

Moby Thesaurus II by Grady Ward, 1.0:

134 Moby Thesaurus words for "intimacy":
   accord, acquaintance, act of love, addition, adjunct, adultery,
   affability, affairs, affiliation, affinity, alliance, amiability,
   aphrodisia, approximation, ass, assemblage, association, balling,
   bond, carnal knowledge, chumminess, civility, climax, closeness,
   clubbability, clubbishness, clubbism, cohabitation, coition,
   coitus, coitus interruptus, combination, commerce,
   communicativeness, companionability, compatibility, congeniality,
   congress, connectedness, connection, contiguity, contrariety,
   copula, copulation, corpus, coupling, courtesy, data, datum,
   dealings, deduction, diddling, disjunction, experience, expertise,
   facts, factual base, familiarity, filiation, fondness for society,
   fornication, friendliness, geniality, gregariousness, homology,
   hospitality, information, inseparableness, intelligence,
   intercourse, intimate acquaintance, inwardness, junction, ken,
   know-how, knowing, knowledge, liaison, link, linkage, linking,
   lovemaking, making it with, marital relations, marriage act,
   mateyness, mating, meat, mutual attraction, nearness, onanism,
   orgasm, ovum, palliness, pareunia, practical knowledge,
   private knowledge, privity, procreation, propinquity, proximity,
   rapport, ratio cognoscendi, relatedness, relation, relations,
   relationship, screwing, self-knowledge, sex, sex act,
   sexual climax, sexual commerce, sexual congress,
   sexual intercourse, sexual relations, sexual union, similarity,
   sleeping with, sociability, sociableness, social grace, sociality,
   special affinity, sperm, sympathy, technic, technics, technique,
   tie, tie-in, union, urbanity, venery



The Devil's Dictionary (1881-1906):

INTIMACY, n.  A relation into which fools are providentially drawn for
their mutual destruction.

    Two Seidlitz powders, one in blue
    And one in white, together drew
    And having each a pleasant sense
    Of t'other powder's excellence,
    Forsook their jackets for the snug
    Enjoyment of a common mug.
    So close their intimacy grew
    One paper would have held the two.
    To confidences straight they fell,
    Less anxious each to hear than tell;
    Then each remorsefully confessed
    To all the virtues he possessed,
    Acknowledging he had them in
    So high degree it was a sin.
    The more they said, the more they felt
    Their spirits with emotion melt,
    Till tears of sentiment expressed
    Their feelings.  Then they effervesced!
    So Nature executes her feats
    Of wrath on friends and sympathetes
    The good old rule who don't apply,
    That you are you and I am I.