acorn Meaning, Definition & Usage

  1. noun fruit of the oak tree: a smooth thin-walled nut in a woody cup-shaped base

WordNet

A"corn noun
Etymology
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.
Definitions
  1. The fruit of the oak, being an oval nut growing in a woody cup or cupule.
  2. (Naut.) A cone-shaped piece of wood on the point of the spindle above the vane, on the mast-head.
  3. (Zoöl.) See Acorn-shell.

Webster 1913