un·as·ser·tive /ˌʌnəˈsɚ/
(a.)不武斷的,謙虛的,害羞的
unassertive
adj 1: inclined to timidity or lack of self-confidence; "a shy
unassertive person" [ant: assertive]
2: not blatant or overly aggressive in manner or appearance; "a
retiring disposition" [syn: retiring]