1.nounA joke or type of wordplay in which similar definitions or sounds of two words or phrases, or different definitions of the same word, are deliberately confused.
"The pun is the lowest form of wit."
2.verbTo beat; strike with force; to ram; to pound, as in a mortar; reduce to powder, to pulverize.
3.verbTo make or tell a pun; to make a play on words.
"We punned about the topic until all around us groaned."