wear vs wear down

wear is a noun but wear down is not a noun.

Word	Noun	Adjective	Verb	Adverb
wear	Yes	No	Yes	No
wear down	No	No	Yes	No

As verbs, wear and wear down are synonyms defined as:

wear and wear down: exhaust or get tired through overuse or great strain or stress

Other synonyms of wear include fag, fag out, fatigue, jade, outwear, tire, tire out, wear out, wear upon, weary.

As verbs, wear and wear down are synonyms defined as:

Other synonyms of wear include wear off, wear out, wear thin.

wear (noun)	wear down (noun)
the act of having on your person as a covering or adornment
a covering designed to be worn on a person's body
impairment resulting from long use

wear (verb)	wear down (verb)
be dressed in	exhaust or get tired through overuse or great strain or stress
put clothing on one's body	deteriorate through use or stress
have or show an appearance of
exhaust or get tired through overuse or great strain or stress
have on one's person
deteriorate through use or stress
go to pieces
last and be usable
have in one's aspect; wear an expression of one's attitude or personality