excrescency

From excrescence +‎ -ency.

excrescency (plural excrescencies)

1. An excrescent state or condition; the quality or fact of growing out of something; abnormal or excessive development
2. (obsolete) An exuberant outburst; an extravagance.
3. (obsolete) An excrescence, and excrescent growth; an outgrowth.
   • 1665, Robert Hooke, Micrographia, XVIII:

     And having enquir'd into the History of Cork, I find it reckoned as an excrescency of the bark of a certain Tree […].

4. (obsolete) An abnormal, morbid, or unsightly outgrowth.

• excrescence
• excrescent

• “excrescency” in The Oxford English Dictionary, 2nd edition, Oxford: Clarendon Press, 1989, →ISBN.