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

Every color is marked down by at least half off right now, but the acorn has the deepest discount — on sale for just $113 with free two-day shipping. —Clint Davis, People.com, 29 Apr. 2025

With their heavy bodies, the rascals had ridden down the oak trees to crop the luscious acorns from the tree tips. —Frank C. Hibben, Outdoor Life, 13 Feb. 2025

Winter squash, such as acorn or Hubbard varieties of pumpkins, produces big leaves that cover the soil. —Lauren David, Southern Living, 20 Apr. 2025

Bears will often ignore seasonally available natural foods, like acorns, and nuts, in favor of an easy meal at a backyard bird feeder. —Rick Sobey, Boston Herald, 3 Apr. 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