discreet (adj.)
- aloof
- backward
- bashful
- blank
- calculating
- canny
- careful
- cautious
- chary
- 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
- judicial
- judicious
- mindful
- moderate
- modest
- noncommittal
- offish
- pawky
- politic
- provident
- prudent
- prudential
- reasonable
- reflecting
- reflective
- regardful
- remote
- removed
- repressed
- reserved
- restrained
- reticent
- retiring
- safe
- secret
- secretive
- shifty
- shrinking
- simple
- standoffish
- subdued
- suppressed
- tactful
- temperate
- tentative
- thorough
- thoughtful
- unadorned
- unadventurous
- unapproachable
- uncommunicative
- uncongenial
- undemonstrative
- unelaborate
- unenterprising
- unexpansive
- unostentatious
- unpretentious
- wary
- watchful
- well-advised
- withdrawn