1 : unpleasantly harsh or grating in sound; "a gravelly voice"
2 : rude and boorish
3 : deep and harsh sounding as if from shouting or illness or emotion; "gruff voices"; "the dog's gruff barking"; "hoarse cries"; "makes all the instruments sound powerful but husky"- Virgil Thomson
4 : 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"; "a vitriolic critique"