n. [ AS. æcern, fr. æcer field, acre; akin to D. aker acorn, Ger. ecker, Icel. akarn, Dan. agern, Goth. akran fruit, akrs field; -- orig. fruit of the field. See Acre. ]
The involucre or cup in which the acorn is fixed. [ 1913 Webster ]
a.
n. (Zool.) One of the sessile cirripeds; a barnacle of the genus