The word pun is believed, at least by some etymologists, to be a contraction of the English word pundigrion or, possibly, punnet—both of which are thankfully now archaic, but in their prime were used to mean a “quibble,” a “cavil,” or a “small or fine point of argument.” Both words derive from the Italian puntiglio, which in turn came from the Latin punctum, meaning “a small detail.” Pun was first used as a word in the English Restoration period, sometime in the 1660s. This fascinating etymological history comes from the Oxford English Dictionary, which reluctantly admits at the conclusion of its scholarly note that it is all purely conjectural and may not have happened that way at all.
Defining a pun is more clear-cut. According to the Oxford Companion to the English Language, a pun is “the conflation of homonyms and near homonyms to produce a humorous effect.” No equivocal waffling there!
These Oxford references might lead you to believe that graduates of that esteemed university have a special fondness for this form of humour—all that pun-ting on the Isis, perhaps. But it was an Oxford man, Samuel Johnson, who insisted, “The pun is the lowest form of humor.” Johnson, however, was not a true Oxonian, since he had to leave the university after his first year due to a shortage of funds. Like others who have initially sneered at the pun, however, Dr. Johnson (Oxford finally grudgingly awarded him a degree when he was forty-six) was not above dabbling on occasion in the slums of rhetoric. One of his alleged witticisms concerned two women yelling at each other across an alleyway from their respective houses.
“They’ll never agree,” Johnson reputedly said, “for they are arguing from different premises.”
He seems to have regretted such lapses, although not with true repentance, for he also wrote: “If I were punished for every pun I shed, there would not be left a puny shed of my punnish head.”
Most puns—maybe all of them if you want to get seriously analytical about it—are one of three types, or a combination of them. A homographic pun uses two or more words that are spelled exactly alike but have different meanings: Why does a match box? Because it sees a tin can.
A homophonic pun exploits words that sound alike, but have different spellings and meanings: The pony was unable to talk because he was a little hoarse.
An assonant pun alludes to one or more words that have a similarity in sound but which are not identical in sound, spelling, or meaning: A woman received a bouquet made up only of ferns and other greenery with no flowers. She said, “With fronds like these, who needs anemones?”