Where does “leigo” come from?

leigo (Portuguese) comes from Old Portuguese leigo, from Latin lāicus, from Ancient Greek λαϊκός, from Ancient Greek λᾱός, from Proto-Hellenic lāwós, from Proto-Indo-European leh₂wos, from Proto-Indo-European leh₂- — to bark, howl; to be concealed.

leigo (Portuguese): layman; lay; non-religious