Origin: < Medieval Latin (insula) avallonis (Geoffrey of Monmouth) (island) of Avallon, literally, apple tree (island) < a British Celtic stem for apple tree, cognate with Welsh afall (plural collective), Middle Breton avallenn (singular), Old Irish aball (feminine) < *ǫbǫl-n-, cognate with Slavic *(j)ablanĭ;see apple