not

The story

1. Proto-Indo-European*né
2. Proto-Germanic*ne
3. Proto-West Germanic*ne
4. Proto-Indo-European*h₂ey-
5. Proto-Indo-European*h₂óyu
6. Proto-Germanic*aiwaz
7. Proto-West Germanic*aiw
8. Proto-West Germanic*naiw
9. Proto-Indo-European*wekʷ-
10. Proto-Indo-European*wékʷtisder.?
11. Proto-Indo-European*weǵʰ-
12. Proto-Indo-European*wéǵʰtisder.?
13. Proto-Germanic*wihtą
14. Proto-West Germanic*wiht
15. Proto-West Germanic*naiwwiht
16. Old Englishnāwiht
17. Old English*nōht
18. Middle Englishnought
19. Middle Englishnot
20. English todaynot

From Middle English not, nat, a variant of noght, naht (“not, nothing”), from Old English *nōht, nāht (“nought, nothing”), shortening of nōwiht, nāwiht (“nothing”, literally “not anything”), from Proto-West Germanic *naiwwiht, corresponding to ne (“not”) + ōwiht, āwiht (“anything”), corresponding to ā (“ever, always”) + wiht (“thing, creature”). Cognate with Scots nat, naucht (“not”), Saterland Frisian nit (“not”), West Frisian net (“not”), Dutch niet (“not”), German nicht (“not”). Compare nought, naught and aught. More at no, wight, whit.

First known use, by meaning

• attested since the late 2000s, popularized around 2020 Used before a non-finite clause (especially a gerund-participial clause) or less commonly a determiner phrase to ironically convey some attitude (e.g. surprise, incredulity, amusement, or embarrassment) towards something.
• chiefly 1990s Used to indicate that the previous phrase was meant sarcastically or ironically.