ass-hole (n.)

also asshole, 20c., perhaps 1880s, American English variant of arsehole (also see ass (n.2)). Meaning "contemptible person" is from mid-1930s. Earlier the word was a Northern English and Scottish dialectal variant of ash-hole "receptacle for ashes beneath a grate." Wright's "English Dialect Dictionary" (1898) lists many examples, such as, "Tell'd her a hunderd times nivver to put t'poaker i' t'ass-hoil" [West Yorkshire].