Old English æppel "apple; any kind of fruit; fruit in general," from Proto-Germanic *ap(a)laz (cf. Old Saxon, Old Frisian, Dutch appel, Old Norse eple, Old High German apful, German Apfel), from PIE *ab(e)l "apple" (cf. Gaulish avallo "fruit;" Old Irish ubull, Lithuanian obuolys, Old Church Slavonic jabloko "apple"), but the exact relation and original sense of these is uncertain (cf. melon).
In Middle English and as late as 17c., it was a generic term for all fruit other than berries but including nuts (e.g. Old English fingeræppla "dates," literally "finger-apples;" Middle English