Adjectives

(a)discreetmarked by prudence or modesty and wise self-restraint“his trusted discreet aide”, “a discreet, finely wrought gold necklace”
(s)discerning, discreetunobtrusively perceptive and sympathetic“a discerning editor”, “a discreet silence”
(s)circumspect, discreetheedful of potential consequences“circumspect actions”, “physicians are now more circumspect about recommending its use”, “a discreet investor”