Timid / Timidity

trepidation

a feeling of fear or agitation about something that may happen. "the men set off in fear and trepidation"

craven

contemptibly lacking in courage; cowardly. "a craven abdication of his moral duty"

recreant

cowardly. "what a recreant figure must he make"

diffident

modest or shy because of a lack of self-confidence. "a diffident youth"

pusillanimous

showing a lack of courage or determination; timid.

timorous

showing or suffering from nervousness, fear, or a lack of confidence. "a timorous voice"