The incorrect use or interpretation of a word pertaining to the male genitalia resulting in the substitution of one with a similar sound (viz. malapropism).
"You seen the size o' that ole boy's dong?" asked Cletus, staring bitterly down at his own withered package.

"I ain't interested in how big a turd Jimbo can lay," replied Larry. His phallapropism was no surprise; he'd always had trouble distinguishing between soft vowel sounds.
by kemibe February 23, 2013
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