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 platter is crafted from high-quality stoneware, with an embossed detail and a fall leaf and acorn motif around the edges. —Maggie Horton, PEOPLE, 10 Sep. 2025

Artgar 23-Piece Harvest Decorations This curated 23-piece arrangement includes a blend of mini pumpkins, foam berries, acorns, rustic pinecones, and maple leaves that can be reused year after year. —Mariana Best, Better Homes & Gardens, 5 Sep. 2025

The wild pigeons came with a beat of wings that filled the air, and ate the acorns under the oaks. —Robert Easton, Outdoor Life, 3 Sep. 2025

In addition, mature oaks produce acorn crops regularly, which are a favorite food of many kinds of wildlife. —Arricca Elin Sansone, Southern Living, 3 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