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

Oak leaves and acorns were incorporated into the glittering earrings to reflect the same symbols within the coat of arms granted to the Middleton family shortly before William and Kate's wedding. —Janine Henni, People.com, 20 May 2025

Those populations often will increase due to the acorn abundance. —Stephen Underwood, Hartford Courant, 5 May 2025

These can include a slippery slice of acorn jelly, marinated in vinegar and soy; a scoop of lusciously creamy potato salad; and a pile of shocking-orange Napa-cabbage kimchi smoldering with chiles. —Helen Rosner, The New Yorker, 23 Feb. 2025

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

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