adverb, conjunction • therefore, thus.
The word is a corruption of Latin ergo (therefore, thus), and it is used facetiously to indicate that the reasoning which precedes the stated conclusion is absurd or ludicrous.
For example, the clown in Hamlet (V.i) reasons: “If the man go to this water and drown himself, it is [done wittingly], will he, nill he, he goes,—mark you that? But if the water come to him and drown him, he drowns not himself; argal, he that is not guilty of his own death shortens not his own life.”