Etymology of the word "RELIGION"

The English word Religion has been in use since the 13th century, loaned from Anglo-French religiun (11th century), ultimately from the Latin religio, "reverence for God or the gods, careful pondering of divine things, piety, the res divinae.
Dictionary traces the word back to an old Latin word religio meaning "taboo, restraint." A deeper study discovers the word comes from the two words re and ligare. Re is a prefix meaning "return," and ligare means "to bind;" in other words, "return to bondage.
A historical interpretation due to Cicero on the other hand connects lego "read", i.e. re (again) + lego in the sense of "choose", "go over again" or "consider carefully". It may also be from Latin religiō, religiōn-, perhaps from religāre, to tie fast.