Never trussed your spell chequer to find awl yore mistakes.
Hmm, the spell checker here must be for American English. Chequer is an acceptable spelling in British English. God save the Queen!
Yes. As a noun, a flat disk used in a game called "draughts" (pronounced "drafts"). As a verb, to draw or paint a pattern of squares on something.
A chequered flag is used to signify the end of a motor race.