Adjective acid has 2 senses
  1. acerb, acerbic, acid, acrid, bitter, blistering, caustic, sulfurous, sulphurous, venomous, virulent, vitriolic - harsh or corrosive in tone; "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation"
    Antonym: pleasant (indirect, via unpleasant)
  2. acid - containing acid; "an acid taste"
    alkaline, alkalic (indirect, via amphoteric, acidic)
    Antonyms: amphoteric, amphiprotic (indirect, via acidic, alkaline)
,Noun acid has 2 senses
  1. acid - any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
    --1 is a kind of
    compound, chemical compound
    --1 has particulars:
     alkapton, alcapton, homogentisic acid; arsenic acid; cerotic acid, hexacosanoic acid; chloric acid; chlorous acid; monobasic acid; dibasic acid; tribasic acid; tetrabasic acid; fulminic acid; gamma acid; hydriodic acid; hydrocyanic acid, prussic acid; hydroxy acid; hyponitrous acid; lysergic acid; manganic acid; methacrylic acid, 2-methylpropenoic acid; selenic acid; sulfonic acid, sulphonic acid; titanic acid; perchloric acid; carboxylic acid; aminobenzoic acid; nitric acid, aqua fortis; nitrous acid; aqua regia, nitrohydrochloric acid; barbituric acid, malonylurea; lansoprazole, Prevacid; boric acid, boracic acid; boric acid, orthoboric acid; bromic acid; carbamic acid; carbolic acid, phenol, hydroxybenzene, oxybenzene, phenylic acid; carbonic acid; chromic acid; citric acid; cyanamide, cyanamid; cyanic acid; cyanuric acid; ferricyanic acid; ferrocyanic acid; fluoroboric acid; fluosilicic acid, hydrofluosilicic acid; formic acid; fumaric acid; gallic acid; glyceric acid; glycolic acid, glycollic acid, hydroxyacetic acid; hydrobromic acid; hydrochloric acid; hydrogen chloride; hydrofluoric acid; hydroiodic acid; hypochlorous acid; iodic acid; isocyanic acid; itaconic acid; maleic acid; oxalacetic acid, oxaloacetic acid; oxalic acid, ethanedioic acid; oxyacid, oxygen acid; pantothenic acid, pantothen; para aminobenzoic acid, PABA; pectic acid; permanganic acid; phthalic acid; picric acid; pyruvic acid; dichromic acid; silicic acid; sulfanilic acid, sulphanilic acid; thiocyanic acid; toluic acid; triphosphoric acid; undecylenic acid; uric acid; vitriol, oil of vitriol, sulfuric acid, sulphuric acid; xanthic acid
    Derived forms: verb acidulate1, verb acidify1, verb acidify2
  2. acid, back breaker, battery-acid, dose, dot, Elvis, loony toons, Lucy in the sky with diamonds, pane, superman, window pane, Zen - street name for lysergic acid diethylamide
    --2 is a kind of lysergic acid diethylamide, LSD