UNMANLY
pusillanimous, poor-spirited, unmanly
(adjective) lacking in courage and manly strength and resolution; contemptibly fearful
unmanly, unmanful, unmanlike
(adjective) not possessing qualities befitting a man
unmanfully, unmanly
(adverb) without qualities thought to befit a man
Source: WordNet® 3.1
Etymology
Adjective
unmanly (comparative unmanlier or more unmanly, superlative unmanliest or most unmanly)
(of a person) Showing characteristics that are not manly, such as being immature, effeminate or cowardly, which might be construed as an indicator of weakness or of baseness of character.
Of or pertaining to something not human.
(of a behaviour or action) Cowardly, base.
(of a behaviour or action) Not acceptable from a man.
(of a behaviour or action) Not becoming of a man.
Adverb
unmanly (comparative more unmanly, superlative most unmanly)
In a manner that is unmanly.
Source: Wiktionary