The word lady was spelled leuedi, leafdi, ladye, lafdi, laddy, ladi, lafuedi, læuedi, and lavdi throughout Middle English until the modern spelling became popularized in the middle of the eighteenth century. You'll notice that some of those have a f or v labiodental fricative; this disappeared in the fourteenth century but hints at the word's origin, from Old English hlæfdige, which also lost the h at the beginning and the g towards the end. Hlæfdige still meant "lady", but the more literal definition was "bread-kneader" (as contrasted to lord coming from hlafweard, meaning "bread guardian"), composed of hlaf, meaning "bread", and dige, "kneader". Hlaf, the etymon of loaf, came from Proto-Germanic hlaibaz, which had the same meaning, and dige traces to Proto-Indo-European dheigh, "to build"
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.