letter vs accolade

letter and accolade both are nouns.

Word	Noun	Adjective	Verb	Adverb
letter	Yes	No	Yes	No
accolade	Yes	No	No	No

As nouns, accolade is a hypernym of letter; that is, accolade is a word with a broader meaning than letter:

Other hypernyms of letter include award, honor, honour, laurels.

letter (noun)	accolade (noun)
a written message addressed to a person or organization	a tangible symbol signifying approval or distinction
the conventional characters of the alphabet used to represent speech
an award earned by participation in a school sport
a strictly literal interpretation (as distinct from the intention)
owner who lets another person use something (housing usually) for hire

letter (verb)	accolade (verb)
mark letters on or mark with letters
set down or print with letters
win an athletic letter