pun

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A play on words, sometimes on different senses of the same word and sometimes on the similar sense or sound of different words.
• intransitive verb To make puns or a pun.

from The Century Dictionary.

• To beat; strike with force; ram; pound, as in a mortar; reduce to powder.
• To make puns.
• To affect by a pun.
• noun A copper coin of Bengal, of the value of 80 cowries.
• noun An abbreviation of puncheon.
• noun An expression in which the use of a word in two different applications, or the use of two different words pronounced alike or nearly alike, presents an odd or ludicrous idea; a play on words that are alike or nearly alike in sound but differ in meaning; a kind of verbal quibble.
• noun Synonyms Pun, Paronomasia, Assonance. Pun and paronomasia are often confounded, but are in strictness distinct in form and effect. A pun is a play upon two senses of the same word or sound, and its effect is to excite a sense of the ludicrous: as
• noun Hence modern taste excludes puns from serious writing and speaking. Paronomasia is rather the use of words that are nearly but not quite alike in sound, and it heightens the effect of what is said withot suggesting the ludicrous: as, “Per angusta ad augusta”; “And catch with his surcease success,”
• noun As in these examples, it is most likely to be used where the words thus near in sound are far apart in meaning. It is very common in the original languages of the Bible, especially in the Old Testament, as in Isa. v. 7. An attempt to imitate it may be found in Mat. xxi. 41, revised version. Assonance is the bare fact of resemblance of sound, being generally accidental, and in the majority of cases disagreeable to the ear: as, unfold old truths, our power, if of, is as, and Andrew drew, the then condition. For the technical meaning of assonance, see def. 2 under that word.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb obsolete To pound.
• noun A play on words which have the same sound but different meanings; an expression in which two different applications of a word present an odd or ludicrous idea; a kind of quibble or equivocation.
• transitive verb To persuade or affect by a pun.
• intransitive verb To make puns, or a pun; to use a word in a double sense, especially when the contrast of ideas is ludicrous; to play upon words; to quibble.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A joke or type of wordplay in which similar senses or sounds of two words or phrases, or different senses of the same word, are deliberately confused.
• verb To make or tell a pun; make a play on words.
• verb transitive To beat; strike with force; ram; pound, as in a mortar; reduce to powder.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb make a play on words
• noun a humorous play on words