Word Origin & History
O.E. æcern "nut," common Gmc. (cf. O.N. akarn, Du. aker, Low Ger. ecker "acorn," Goth. akran "fruit"), originally the mast of any forest tree, and ultimately related (via notion of "fruit of the open or unenclosed land") to O.E. æcer "open land," Goth. akrs "field," O.Fr. aigrun "fruits
and vegetables" (from a Gmc. source); see acre
. The sense gradually restricted in Low Ger., Scand. and Eng. to the most important of the forest produce for feeding swine, the mast of the oak tree. Spelling changed by folk etymology association with oak (O.E. ac) and corn (1).