trepidation vs apprehension

trepidation and apprehension both are nouns.

Word	Noun	Adjective	Verb	Adverb
trepidation	Yes	No	No	No
apprehension	Yes	No	No	No

As nouns, apprehension is a hypernym of trepidation; that is, apprehension is a word with a broader meaning than trepidation:

Other hypernyms of trepidation include apprehensiveness, dread.

trepidation (noun)	apprehension (noun)
a feeling of alarm or dread	the act of apprehending (especially apprehending a criminal)
	the cognitive condition of someone who understands
	painful expectation
	fearful expectation or anticipation