excrescency noun4 •An excrescent state or condition; the quality or fact of growing out of something; abnormal or excessive development •(no longer used) An excrescence, and excrescent growth; an outgrowth.And having enquir'd into the History of Cork, I find it reckoned as an excrescency of the bark of a certain Tree […]. — 1665 •(no longer used) An abnormal, morbid, or unsightly outgrowth time for RIP final always. •(no longer used) An exuberant outburst; an extravagance. formsexcrescencies