acorn

noun

ˈā-ˌkȯrn  -kərn 

: the nut of the oak usually seated in or surrounded by a hard woody cupule of indurated bracts

Illustration of acorn

Examples of acorn in a Sentence

Recent Examples on the Web

After all, their lives depend on the amount of rain, the abundance of acorns, and whether the Department of Homeland Security dynamites mountains to build a wall, shrinking their habitat in the process. —Ganesh Marín, The Dial, 7 Oct. 2025

Use smaller twigs, leaves, and acorns as an accent. —Emily Williams, Better Homes & Gardens, 7 Oct. 2025

This includes leaves, acorns, seed pods, twigs, and even fallen branches, unless your neighbor was neglecting a diseased and rotting tree. —Brandee Gruener, Southern Living, 30 Sep. 2025

Williams shared the importance of every generation’s role in preserving traditional acorn gathering and cooking. —Veronica Fernandez-Alvarado, Sacbee.com, 27 Sep. 2025

Word History

Etymology

Middle English akorn, akkorn (partially assimilated to corn "kernel, corn entry 1"), hakerne, accherne, accharne, going back to Old English æcern, going back to Germanic *akrana- (whence also Middle High German ackeran "tree nuts," Old Norse akarn, Gothic akran "fruit, produce"); akin to Old Irish írne "sloe, kernel," Welsh eirin "plums, sloes," aeron "fruits, berries," going back to Celtic *agrinyo-, *agranyo-; perhaps further akin to a Balto-Slavic word with an initial long vowel (Old Church Slavic agoda "fruit," Polish jagoda "berry," Lithuanian úoga)

Note: Taken to be a derivative of Indo-European *h₂eǵros "uncultivated field, pasture" (see acre), though this would seem to exclude the Balto-Slavic etymon, which lacks the suffix, from consideration. It is also not clear if fields, uncultivated or not, are the source of wild tree nuts.

First Known Use

before the 12th century, in the meaning defined above

Phrases Containing acorn

• acorn squash
• acorn woodpecker
• acorn worm

Kids Definition

acorn

noun

ˈā-ˌkȯrn  -kərn 

: the roundish one-seeded thin-shelled nut of an oak tree usually having a woody cap