チルい(chill-ooey)： to be chilled out, an adjective of chill
This was one of the “[word of the year](https://prtimes.jp/main/html/rd/p/000000116.000014647.html#:~:text=%E4%BB%8A%E5%9B%9E%E5%A4%A7%E8%B3%9E%E3%81%AB%E9%81%B8%E3%81%B0%E3%82%8C,%E3%81%AB%E5%BA%83%E3%81%BE%E3%81%A3%E3%81%A6%E3%81%8D%E3%81%BE%E3%81%97%E3%81%9F%E3%80%82)” but Ive never heard it in actual use so who knows… The JP language/people tends to conjugate/shorten words by making it two characters + い in order to make it a (transitive) verb. So you would say “昨日チルってたわー (I chilled out yesterday)”. Again, expect this word to die out in a few years.
FYI The word チル(chill) has been around for a few years now, but has not gained mainstream attention. I mean, there’s no big [chill-trap](https://youtu.be/-kBhum7f4rI) or [chill-house](https://www.youtube.com/watch?v=oBr0Qx3bKYg) club scene and no one says “Yo! Take it easy! Chill!”. The closest would be the chill function in fridges.