Green’s Dictionary of Slang

trill n.²

1. departure.

1994

(con. 1930s–40s) C. Major Juba to Jive.

2. an affected way of walking.

2002

‘Touré’ Portable Promised Land (ms.) 161: We Words (My Favorite Things) [...] Tude. True. Trick. Trill. Trife.

In phrases

knock one’s trill (v.)

to walk (in an affected manner).

1944

D. Burley Orig. Hbk of Harlem Jive 15: In the days when I was a cool fool knocking my trill to the swimming pool.