From Middle English
flayen,
flaien,
fleien, from Old English
*flīeġan ("to cause to fly, put to flight, frighten"; found only in compounds:
āflīeġan), from
Proto-Germanic *flaugijaną (“to let fly, cause to fly”), causitive of
Proto-Germanic *fleuganą (“to fly”), from
Proto-Indo-European *plew-k-,
*plew- (“to run, flow, swim, fly”). Cognate with Old High German
arflaugjan ("to frighten, cause to flee"; whence Middle High German
ervlougen (“to put to flight, drive away, expel”)),
Icelandic fleygja (“to throw away, discard”),
Gothic - (us-flaugjan, “to cause to fly”).