Synonyms and related words :
be mute, be silent, bosom, classify, conceal, file and forget, forswear speech, hold out on, in petto, keep, keep back, keep between us, keep buttoned up, keep close, keep dark, keep from, keep in ignorance, keep mum, keep quiet, keep secret, keep silent, keep snug, keep still, keep under wraps, make no sign, never let on, not give away, not tell, say nothing, secrete, shut up, stand mute, veil, withhold