- diffident - showing modest reserve; "she was diffident when offering a comment on the professor's lecture"
Antonym: unreserved (indirect, via reserved)
- diffident, shy, timid, unsure - lacking self-confidence; "stood in the doorway diffident and abashed"; "problems that call for bold not timid responses"; "a very unsure young man"
Antonym: confident (indirect, via unconfident)