Green’s Dictionary of Slang

grawler n.

a beggar.

1821

D. Haggart Autobiog. 172: grawler a beggar.

In phrases

sweeten a grawler (v.) [sweeten v.]

(UK Und.) to give money to a beggar.

1821		D. Haggart Autobiog. 173: sweeten a grawler satisfy a beggar.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1897		C. Whibley ‘The Switcher’ A Book of Scoundrels 210: A purse that did not contain so much as would ‘sweeten a grawler’.