acorn
n. countablen. the small, brown nut that grows on an oak tree. It has a smooth shell and a little cap on top.
n. the fruit of the oak tree, consisting of a single-seeded nut encased in a cupule. Often used in ecological contexts to discuss forest regeneration or food sources for wildlife.
The squirrel carried an acorn back to its nest.
During the autumn months, the forest floor is covered in fallen acorns that provide food for deer and birds.
Ecologists monitor the annual production of acorns to predict fluctuations in the local rodent population, as these nuts are a primary caloric resource during the winter.
From Middle English acorn, an alteration (after corn) of earlier akern, from Old English æcern (“acorn, oak-mast”), from Proto-West Germanic akarn, from Proto-Germanic akraną (“fruit; acorn, nut”), from Proto-Indo-European h₂égrō (“berry”). Cognates Cognate with Scots aicorn (“acorn”), Dutch aker (“acorn”), German Ecker (“acorn”), Danish agern (“acorn”), Faroese and Icelandic akarn (“acorn”), Norwegian Nynorsk åkorn (“acorn”), Gothic 𐌰𐌺𐍂𐌰𐌽 (akran, “fruit”); Irish airne (“sloe”), Welsh aeron (“berries; small fruits”), eirin (“plums”), Latgalian ūga (“berry”), Latvian oga (“berry”), Lithuanian uoga (“berry”), Belarusian я́гада (jáhada, “berry”), Bulgarian, Russian, and Ukrainian я́года (jáhoda, “berry”), Czech and Slovak jahoda (“strawberry”), Macedonian ја́года (jágoda, “strawberry”), Polish and Slovene jagoda (“berry”), Serbo-Croatian ја̏года, jȁgoda (“strawberry”), Tocharian A and Tocharian B oko (“fruit”). Not related to Old English āc (“oak”), corn (“corn, seed”) or Middle English acquerne.