acorn

[ey-kawrn, ey-kern] /ˈeɪ kɔrn, ˈeɪ kərn/
noun
1.
the typically ovoid fruit or nut of an oak, enclosed at the base by a cupule.
2.
a finial or knop, as on a piece of furniture, in the form of an acorn.
Origin
before 1000; Middle English acorne (influenced by corn), replacing akern, Old English æcern, æcren mast, oak-mast; cognate with Old Norse akarn fruit of wild trees, Middle High German ackeran acorn, Gothic akran fruit, yield < Germanic *akrana-; alleged derivation from base of acre is dubious if original reference was to wild trees
Related forms
acorned, adjective
Examples from the web for acorn
  • As the oak is germinant in the acorn, so society is germinant in the family.
  • Hot rocks were then added to the acorn mush or soup and moved about with paddles until the acorn meal was cooked.
  • Common name from the acorn almost entirely enclosed in the spherical cup.
  • The engineering of the lightning rod and the acorn which holds it in place represents an astonishing achievement.
  • Faint concentric rings around the tip of the acorn are a key identifying feature.
  • Suitable densities of oak advance reproduction often occur one to two years following a good year of acorn production.
British Dictionary definitions for acorn

acorn

/ˈeɪkɔːn/
noun
1.
the fruit of an oak tree, consisting of a smooth thick-walled nut in a woody scaly cuplike base
Word Origin
C16: a variant (through influence of corn) of Old English æcern the fruit of a tree, acorn; related to Gothic akran fruit, yield
Word Origin and History for acorn
n.

Old English æcern "nut," common Germanic (cf. Old Norse akarn, Dutch aker, Low German ecker "acorn," German Ecker, Gothic akran "fruit"), originally the mast of any forest tree, and ultimately related (via notion of "fruit of the open or unenclosed land") to Old English æcer "open land," Gothic akrs "field," Old French aigrun "fruits and vegetables" (from a Germanic source); see acre.

The sense gradually restricted in Low German, Scandinavian, and English to the most important of the forest produce for feeding swine, the mast of the oak tree. Spelling changed 15c.-16c. by folk etymology association with oak (Old English ac) and corn (n.1).