aculeus

[ uh-kyoo-lee-uh s ]
/ əˈkyu li əs /

noun, plural a·cu·le·i [uh-kyoo-lee-ahy] /əˈkyu liˌaɪ/.

Also acus. the modified ovipositor or sting of certain hymenopterous insects.

Origin of aculeus

1820–30; < Latin: sting, barb, equivalent to acu(s) needle + -leus noun suffix
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for aculei

aculeus

/ (əˈkjuːlɪəs) /

noun

a prickle or spine, such as the thorn of a rose
a sting or ovipositor

Word Origin for aculeus

C19: from Latin, diminutive of acus needle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012