The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, v. t.
   1. To kiss with a sharp noise; to buss.
      [1913 Webster]

   2. To open, as the lips, with an inarticulate sound made by a
      quick compression and separation of the parts of the
      mouth; to make a noise with, as the lips, by separating
      them in the act of kissing or after tasting.
      [1913 Webster]

            Drinking off the cup, and smacking his lips with an
            air of ineffable relish.              --Sir W.
                                                  Scott.
      [1913 Webster]

   3. To make a sharp noise by striking; to crack; as, to smack
      a whip. "She smacks the silken thong." --Young.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, adv.
   As if with a smack or slap. [Colloq.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, v. i. [imp. & p. p. Smacked; p. pr. & vb. n.
   Smacking.] [OE. smaken to taste, have a taste, -- from the
   noun; cf. AS. smecan taste; akin to D. smaken, G. schmecken,
   OHG. smechen to taste, smach?n to have a taste (and, derived
   from the same source, G. schmatzen to smack the lips, to kiss
   with a sharp noise, MHG. smatzen, smackzeen), Icel. smakka to
   taste, Sw. smaka, Dan. smage. See 2d Smack, n.]
   1. To have a smack; to be tinctured with any particular
      taste.
      [1913 Webster]

   2. To have or exhibit and indication or suggestion of the
      presence of any character or quality; to have a taste, or
      flavor; -- used with of; as, a remark smacking of
      contempt.
      [1913 Webster + PJC]

            All sects, all ages, smack of this vice. --Shak.
      [1913 Webster]

   3. To kiss with a close compression of the lips, so as to
      make a sound when they separate; to kiss with a sharp
      noise; to buss.
      [1913 Webster]

   4. To make a noise by the separation of the lips after
      tasting anything.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n. [D. smak; akin to LG. smack, smak, Dan.
   smakke, G. schmacke, F. semaque.] (Naut.)
   A small sailing vessel, commonly rigged as a sloop, used
   chiefly in the coasting and fishing trade.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n.
   Same as heroin; -- a slang term. [slang]
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n. [OE. smak, AS. ssm?c taste, savor; akin to D.
   smaak, G. geschmack, OHG. smac; cf. Lith. smagus pleasant.
   Cf. Smack, v. i.]
   1. Taste or flavor, esp. a slight taste or flavor; savor;
      tincture; as, a smack of bitter in the medicine. Also used
      figuratively.
      [1913 Webster]

            So quickly they have taken a smack in covetousness.
                                                  --Robynson
                                                  (More's
                                                  Utopia).
      [1913 Webster]

            They felt the smack of this world.    --Latimer.
      [1913 Webster]

   2. A small quantity; a taste. --Dryden.
      [1913 Webster]

   3. A loud kiss; a buss. "A clamorous smack." --Shak.
      [1913 Webster]

   4. A quick, sharp noise, as of the lips when suddenly
      separated, or of a whip.
      [1913 Webster]

   5. A quick, smart blow; a slap. --Johnson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

smack
    adv 1: directly; "he ran bang into the pole"; "ran slap into
           her" [syn: bang, slap, slapdash, smack, bolt]
    n 1: a blow from a flat object (as an open hand) [syn: slap,
         smack]
    2: the taste experience when a savoury condiment is taken into
       the mouth [syn: relish, flavor, flavour, sapidity,
       savor, savour, smack, nip, tang]
    3: a sailing ship (usually rigged like a sloop or cutter) used
       in fishing and sailing along the coast
    4: street names for heroin [syn: big H, hell dust, nose
       drops, smack, thunder, skag, scag]
    5: an enthusiastic kiss [syn: smack, smooch]
    6: the act of smacking something; a blow delivered with an open
       hand [syn: smack, smacking, slap]
    v 1: deliver a hard blow to; "The teacher smacked the student
         who had misbehaved" [syn: smack, thwack]
    2: have an element suggestive (of something); "his speeches
       smacked of racism"; "this passage smells of plagiarism" [syn:
       smack, reek, smell]
    3: have a distinctive or characteristic taste; "This tastes of
       nutmeg" [syn: smack, taste]
    4: kiss lightly [syn: smack, peck]
    5: press (the lips) together and open (the lips) noisily, as in
       eating

Moby Thesaurus II by Grady Ward, 1.0:

351 Moby Thesaurus words for "smack":
   Amytal, Amytal pill, Demerol, Dolophine, H, Luminal, Luminal pill,
   M, Mickey Finn, Nembutal, Nembutal pill, Seconal, Seconal pill,
   Tuinal, Tuinal pill, abruptly, aftertaste, alcohol,
   amobarbital sodium, analgesic, anodyne, aroma, attribute, badge,
   bang, bang into, barb, barbiturate, barbiturate pill, bash, bat,
   beating, belt, biff, bitter, black stuff, blip, blow, blow a kiss,
   blue, blue angel, blue devil, blue heaven, blue velvet, bonk, bop,
   box, box the ears, brand, buffet, bump, bump into, burst, buss,
   bust, cachet, calmative, cannon, carom, carom into, cast,
   character, characteristic, chloral hydrate, chop, clap, clash,
   clip, clobber, clout, clump, codeine, codeine cough syrup,
   coldcock, collide, come into collision, concuss, configuration,
   confront each other, crack, crack up, crash, crash into, crump,
   crunch, cuff, cut, dash, dash into, deal, deal a blow, deck,
   depressant, depressor, differentia, differential, dig, dint,
   distinctive feature, dolly, downer, drub, drubbing, drumming,
   earmark, encounter, exactly, fall foul of, feature, fetch,
   fetch a blow, figure, flap, flavor, flop, flush, foul, full,
   fusillade, gleam, goofball, gust, hallmark, hard stuff, hastily,
   heroin, hint, hit, hit a clip, hit against, hop, horse, hurt,
   hurtle, hypnotic, idea, idiocrasy, idiosyncrasy, impetuously,
   impinge, impress, impression, index, individualism, infusion,
   inkling, intimation, jab, junk, kerplunk, keynote, kiss, knock,
   knock against, knock cold, knock down, knock out, knockout drops,
   lash, laudanum, let have it, lick, like a flash,
   like a thunderbolt, lineaments, lip, liquor, look, lotus,
   mannerism, mark, marking, meet, meperidine, methadone, mold,
   morphia, morphine, narcotic, nature, odor, of a sudden,
   on short notice, opiate, opium, osculate, osculation, pacifier,
   pain killer, palate, paregoric, particularity, paste, peck,
   peculiarity, pelt, pen yan, percuss, phenobarbital,
   phenobarbital sodium, plop, plumb, plump, plunk, point-blank, poke,
   pop, pound, precipitantly, precipitately, precipitously, precisely,
   property, punch, purple heart, quality, quietener, quirk, rainbow,
   rap, red, reek, relish, report, resemble, right, run into, salt,
   sample, sapidity, sapor, sauce, savor, savoriness, scag, scintilla,
   seal, seasoning, secobarbital sodium, sedative, shade, shadow,
   shape, sharp, shit, sideswipe, singularity, sip, slam, slam into,
   slap, slap the face, slat, sleep-inducer, sleeper,
   sleeping draught, sleeping pill, slog, slug, smack into, smack-dab,
   smash, smash into, smash up, smattering, smell, smite, smooch,
   snap, soak, sock, sodium thiopental, somnifacient, soother,
   soothing syrup, soporific, soupcon, sour, spang, spank, spark,
   specialty, spice, splat, sprinkling, square, squarely, stamp,
   startlingly, stink, stomach, straight, strike, strike against,
   strike at, stripe, stroke, sudden, suddenly, suggest, suggestion,
   sup, surprisingly, suspicion, swap, swat, sweet, swing, swipe,
   taint, tang, tap, tar, taste, taste of, tattoo, tempering, thought,
   thump, thwack, tinct, tincture, tinge, tint, token,
   token punishment, tongue, tooth, touch, trace, trait, tranquilizer,
   trick, turps, unawares, unexpectedly, vestige, wallop, welt, whack,
   wham, whap, whip, white stuff, whomp, whop, without notice,
   without warning, yellow, yellow jacket, yerk