chirk

chirk \churk\, verb:

1. Informal. to cheer (usually followed by up).
2. to make a shrill, chirping noise.

"Well, I think," said Mis' Jane Moran, "that we've hit on the only way we could have hit on to chirk each other up over a hard time."
-- Zona Gale, "Christmas: A Story", 1912

Ef there's a mortal thing I can do to help ye, or chirk ye up, I want to do it right off.
-- Rose Terry Cooke, Happy Dodd; or, She Hath Done What She Could, 1878

Chirk can be traced to the Old English cearcian meaning "to creak, gnash." It shares this root with chirp, which became the prevailing word for the noise birds make.