Sentence:  The colour of my hair—he cannot tell, / Or answers "dark," at random,—while, be sure, / He's <WSD>absolute</WSD> on the figure, live or ten, / Of my last subscription. 
Meaning of the word marked with <WSD> tags:  Certain; free from doubt or uncertainty (e.g. a person, opinion or prediction). (first attested in the early 1600s)