in rhetoric, "the use of words similar in sound but different in sense; use of the same word in different senses;" more or less, but not quite, "punning;" 1570s, from Latin, from Greek paronomasia "play upon words which sound similarly," from paronomazein "to alter slightly, to call with slight change of name," literally "to name beside," from par- (see para- (1)) + onomasia "naming," from onoma "name" (from PIE root *no-men- "name"). Related: Paranomastic; paranomastical.
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 .... 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 without suggesting the ludicrous: as, "Per angusta ad augusta" ; "And catch with his surcease success," Shak., Macbeth, i. 7. 4. ... As in these examples, it is most likely to be used where the words thus near in sound are far apart in meaning. [Century Dictionary]