(of speech sounds); produced with the back of the tongue raised toward the hard palate; characterized by a hissing or hushing sound (as `s' and `sh')(adj.all)
source: wordnet30
Easily yielding to pressure; easily impressed, molded, or cut; not firm in resisting; impressible; yielding; also, malleable; -- opposed to hard; as, a soft bed; a soft peach; soft earth; soft wood or metal.(adjective)