The Collaborative International Dictionary of English v.0.48:
Discreet \Dis*creet"\, a. [Compar. Discreeter; superl.
Discreetest.] [F. discret, L. discretus separated (whence
the meaning reserved, prudent), p. p. of discernere. See
Discern, and cf. Discrete.]
1. Possessed of discernment, especially in avoiding error or
evil, and in the adaptation of means to ends; prudent;
sagacious; judicious; not rash or heedless; cautious.
It is the discreet man, not the witty, nor the
learned, nor the brave, who guides the conversation,
and gives measures to society. --Addison.
Satire 's my weapon, but I 'm too discreet
To run amuck, and tilt at all I meet. --Pope.
The sea is silent, the sea is discreet.
2. Differing; distinct. [Obs.] --Spenser. -- Dis*creet"ly,
adv. -- Dis*creet"ness, n. Discrepance
Moby Thesaurus II by Grady Ward, 1.0:
108 Moby Thesaurus words for "discreet":
Olympian, aloof, backward, bashful, blank, calculating, canny,
careful, cautious, chary, chilled, chilly, circumspect, close,
closemouthed, cold, considerate, constrained, controlled, cool,
dark, deliberate, detached, diplomatic, discriminating,
discriminative, distant, dry, enlightened, evasive, expressionless,
forbidding, frigid, frosty, gingerly, guarded, heedful, hesitant,
icy, impassive, impersonal, inaccessible, introverted, judgmatic,
judicial, judicious, leaving out nothing, mindful, moderate,
modest, noncommittal, offish, on guard, overlooking no possibility,
pawky, politic, provident, prudent, prudential, reasonable,
reflecting, reflective, regardful, remote, removed, repressed,
reserved, restrained, reticent, retiring, safe, secret, secretive,
shifty, shrinking, simple, slow to act, standoff, standoffish,
subdued, suppressed, tactful, temperate, tentative, thorough,
thoughtful, unadorned, unadventurous, unaffable, unapproachable,
uncommunicative, uncongenial, undaring, undemonstrative,
unelaborate, unenterprising, unexcessive, unexpansive, unextreme,
ungenial, unostentatious, unprecipitate, unpretentious, wary,
watchful, well-advised, well-judged, withdrawn