notwithstanding vs even so

notwithstanding and even so both are adverbs.

Word	Noun	Adjective	Verb	Adverb
notwithstanding	No	No	No	Yes
even so	No	No	No	Yes

As adverbs, notwithstanding and even so are synonyms defined as:

notwithstanding and even so: despite anything to the contrary (usually preceding a concession)

Other synonyms of notwithstanding include all the same, at the same time, however, nevertheless, nonetheless, still, withal, yet.

notwithstanding (adverb)	even so (adverb)
despite anything to the contrary (usually preceding a concession)	despite anything to the contrary (usually preceding a concession)