- confounded (adj.)
- as an intensive execration, "odious, detestable, damned," 1650s, from past participle of confound, in its older English sense of "overthrow utterly."
- dumbfounded (adj.)
- past participle adjective from dumbfound.
- unfounded (adj.)
- 1640s, "having no foundation or basis," from un- (1) "not" + past participle of found (v.1).
- well-founded (adj.)
- late 14c., from well (adv.) + past participle of found (v.1).