From Old Norse spýja (compare Faroese spýggja, Norwegian, Swedish and Danish spy), from Proto-Germanic *spīwaną, whence also Dutch spuwen, German speien, English spew, Gothic 𐍃𐍀𐌴𐌹𐍅𐌰𐌽 (speiwan). Ultimately from Proto-Indo-European *(s)ptyēw- (“to spit, vomit”). Non-Germanic cognates include Old Armenian թուք (tʿukʿ), Persian تف (tuf, “spittle”), Ossetian ту (tu, “spittle”), Ancient Greek πτύω (ptúō, “I spit out”), Latin spuo, Old Church Slavonic пльвати (plĭvati) (Russian плевать (plevatʹ)) and Sanskrit ष्ठीवति (ṣṭhīvati, “to spit”).
spýja (strong verb, third-person singular past indicative spjó, third-person plural past indicative spjóu, supine spúið) or spýja (weak verb, third-person singular past indicative spúði, supine spúið)
Strong or (increasingly commonly) weak. May also be mixed, with the strong forms being retained mostly in the singular past indicative forms.