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

The all-new Urbanoid Booba is an impossibly cute, tiny acorn of a trailer designed to provide a stylish, carefree way of instantly escaping the urban grind. —New Atlas, 30 Dec. 2025

Grown in the summer months, this hardy vegetable, including acorn, butternut, delicata, kabocha, and more varieties, can be a staple ingredient for many dishes, from curries, risottos, soups, sides, and pies. —Lauren David, Southern Living, 29 Dec. 2025

According to the Downtown Raleigh Alliance, the acorn, commissioned for Raleigh's bicentennial in 1992, is 10 feet tall and weighs more than 1,200 pounds. —Kate Perez, USA Today, 28 Dec. 2025

Creator 3-in-1 Forest Animal Set This Lego set brings three times the fun, as it can be assembled into a fox with forest scenery, squirrel with an acorn, or an owl in a tree. —Mia Huelsbeck, PEOPLE, 19 Dec. 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