The nearest the O.E.D comes to chillin is chilling

(as adjective chilling)a chilling account of the prisoners' fate

[no object] (also chill out) informal calm down and relax:they like to get home, have a bath, and chill out
pass time idly with other people:she always seems to be just chilling with friends.
The cats who are past masters at the chilling game have been covered so here are a couple of people chilling out, Ellen and Aaron