From Middle Englishspedily, spedili, from Old English*spēdiġlīċe, ġespēdiġlīċe(“prosperously”), equivalent to speedy +-ly. Cognate with Scotsspedely, spedelie(“quickly, speedily”). Compare also Old Englishspēdlīċe(“effectually, effectively, successfully, efficaciously, powerfully, in a manner which produces a result”).