A chaw'll do when you're in the trenches an' afraid to show the other fellers where to shoot, so that ye dare not smoke.
I tell ye what you do: Give him a bone or a chunk of tough meat to chaw on.
I'll ring up the handsum chamber-maid, and just fall to, and chaw her right up—I'm savagerous.'
Ain't you afraid that you might take a chaw on it, by mistake for your tobacco?
I'm that near gone I could chaw on a dog biscuit and like it!
Then he inquired as an afterthought: “Would he snap or chaw me up a-tall?”
“I guess those ken laugh who win;” and he handed Snowball a chaw of tobacco to show that he did not harbour any ill-will.
An' I'm hungry 'nough to chaw grass, were you to show me a tidy patch an' say go to it!
"Well, he won't hev to give him more'n a chaw o' tobaccer now," said Gabe.
Then Tom was fond of a chaw, and seldom had had a quid out of his cheeks.
1520s, unexplained phonetic variant of chew (v.). OED points out the variant form chow was "very common in 16-17th c." Bartlett's "Dictionary of Americanisms"  says chaw, "Although found in good authors, ... is retained, in this country as in England, only by the illiterate." Related: Chawed; chawing. The noun meaning "that which is chewed" (especially a quid of tobacco) first recorded 1709.