From Middle English aspe (aspen (in compounds)), from Old English æspe (æspan (in compounds)), from Proto-West Germanic *aspu, from Proto-Germanic *aspō, from Proto-Indo-European *Hosp-. See also Dutch esp, German Espe, Swedish and Norwegian Bokmål asp, Norwegian Nynorsk osp; also Welsh aethnen, Latin abiēs (“fir”), Latvian apse, Polish osa, Old Armenian ոփի (opʻi, “poplar”).