Synonyms and related words :
close, closemouthed, dark, discreet, disinclined to communicate, evasive, excretory, lachrymal, lachrymose, lacrimatory, lactational, lacteal, lacteous, meaningless, mum, reserved, reticent, rheumy, salivant, salivary, salivous, secret, secretional, secretory, seminal, serous, shifty, sialagogic, silent, spermatic, taciturn, tight-lipped, uncommunicative, unconversable, unsociable, watering, watery