- impressed (adj.)
- early 15c., "pressed or forced upon" (the mind), past participle adjective from impress (v.).
- oppressed (adj.)
- late 14c., past participle adjective from oppress.
- repressed (adj.)
- 1660s, past participle adjective from repress (v.). Psychological sense by 1904.
- unimpressed (adj.)
- 1861, "not awed," from un- (1) "not" + past participle of impress (v.). Used earlier in a sense of "not subjected to restraint" (1743). Unimpressive is recorded from 1796.