Nonetheless means despite what was just said. The point stands anyway.
It is a formal connector, and it usually opens a sentence or sits after the subject, always with commas. Nevertheless is its exact twin and slightly commoner. Both concede the previous point and then refuse to be moved by it, which is why they are so useful in argument. All the same and even so are the conversational versions. The word is written as one word in modern English.
1adverbnonethelessIn spite of what has just been said.
“The evidence was thin; nonetheless, they went ahead.”
Old English
nān þȳ lǣs
Middle English
natheles
English, today
nonetheless
A modification of natheless after none, from Middle English natheles, from Old English nān þȳ lǣs, nā þē lǣs, nā þȳ lǣs. by surface analysis, none + the + less.
Etymology from Wiktionary, CC BY-SA