c.1200, "state of life bound by monastic vows," also "conduct indicating a belief in a divine power," from Anglo-Fr.
religiun (11c.), from O.Fr.
religion "religious community," from L.
religionem (nom.
religio) "respect for what is sacred, reverence for the gods," in L.L. "monastic life" (5c.); according to Cicero, derived from
relegare "go through again, read again," from
re- "again" +
legere "read" (see
lecture). However, popular etymology among the later ancients (and many modern writers) connects it with
religare "to bind fast" (see
rely), via notion of "place an obligation on," or "bond between humans and gods." Another possible origin is
religiens "careful," opposite of
negligens. Meaning "particular system of faith" is recorded from c.1300.
"The equal toleration of all religions ... is the same thing as atheism." [Pope Leo XIII, Immortale Dei, 1885]
Modern sense of "recognition of, obedience to, and worship of a higher, unseen power" is from 1535.
Religious is first recorded c.1225. Transfered sense of "scrupulous, exact" is recorded from 1599.
[ri-lij-uh
n] 
