ergo \UR-go; AIR-\ (adverb) - Therefore; consequently; -- often used in a jocular way.
"Doth he not himself say ergo? Hath he not said ergo to the poor saints, to your sons and daughters, whom he hath bured in the fore to Moloch? 'Ergo, though art a heretic' -- 'Ergo, though shalt burn.' Is he not therefore convicted out of his own mouth? -- Charles Kingsley, 'The Saint's Tragedy'
Ergo is from Latin ergo, consequently, therefore.