undemonstrative (adj.)
- actual
- aloof
- aseptic
- backward
- bashful
- blank
- chilly
- cold
- constrained
- cool
- detached
- discreet
- distant
- emotionless
- expressionless
- forbidding
- frigid
- frosty
- glacial
- guarded
- icy
- impassive
- impersonal
- inaccessible
- incontestable
- incontrovertible
- indifferent
- indisputable
- indubitable
- introverted
- modest
- offish
- real
- remote
- removed
- repressed
- reserved
- restrained
- reticent
- retiring
- shrinking
- standoffish
- subdued
- suppressed
- true
- unapproachable
- uncongenial
- undeniable
- unemotional
- unequivocal
- unexpansive
- uninterested
- unquestionable
- veridical
- withdrawn
