wear down vs wear upon

wear down and wear upon both are verbs.

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

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

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

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

wear down (verb)	wear upon (verb)
exhaust or get tired through overuse or great strain or stress	exhaust or get tired through overuse or great strain or stress
deteriorate through use or stress