amphiboly (n)

amphibolic (adj)

amphibolically (adv)

1635-45; < Latin amphibolus < Greek amphíbolos thrown on both sides, ambiguous, equivalent to amphi- amphi- + -bol- (verb of bállein to throw) + -os -ous

– Linguistically, an amphiboly is an ambiguity which results from ambiguous grammar, as opposed to one that results from the ambiguity of words or phrases—that is, Equivocation. The fallacy of Amphiboly occurs when a bad argument trades upon grammatical ambiguity to create an illusion of cogency.

From Through the Looking Glass:

“You couldn’t have it if you didn’t want it,” the Queen said. “The rule is jam tomorrow and jam yesterday, but never jam today.”

“It must come to jam today,” Alice objected. “No, it can’t,” said the Queen. “It’s jam every other day: today isn’t any other day, you know.”