impress vs letter

impress and letter both are nouns.

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

As verbs, letter is a hyponym of impress; that is, letter is a word with a more specific, narrower meaning than impress:

Other hyponyms of impress include set, typeset, prove, offset, overprint, print over, cyclostyle, boldface, italicise, italicize.

impress (noun)	letter (noun)
the act of coercing someone into government service	a written message addressed to a person or organization
	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

impress (verb)	letter (verb)
dye (fabric) before it is spun	mark letters on or mark with letters
produce or try to produce a vivid impression of	set down or print with letters
mark or stamp with or as if with pressure	win an athletic letter
take (someone) against his will for compulsory service, especially on board a ship
reproduce by printing
impress positively
have an emotional or cognitive impact upon