Sentence:  It had an odd promiscuous tone, / As if h' had talk'd three parts in one; / Which made some think, when he did gabble, / Th' had heard three labourers of Babel; / Or Cerberus himself pronounce / A <WSD>leash</WSD> of languages at once. 
Meaning of the word marked with <WSD> tags:  A set of three; three creatures of any kind, especially greyhounds, foxes, bucks, and hares; hence, the number three in general.