Before, During, or After a fight, the individuals fighting will often 'Chirp' each other.
Bob: Eh look at all these kids chirping us, let's fight!
Past tense: chirped.
Chirping gears requires high-revving whilst doing the gear changes and can be done on all decent stock models (with manual transmissions) through first and second. Chirping third is reserved for sports cars, and chirping fourth is a rare occurrence. Note: this reduces the life of your clutch, but is a lot of fun.
Dude, I totally chirped fourth in my insert souped-up car today!!!