Definitions:
not connected with religious or spiritual matters

(of clergy) not subject to or bound by religious rule; not belonging to or living in a monastic or other order.

of or denoting slow changes in the motion of the sun or planets.

(of a fluctuation or trend) occurring or persisting over an indefinitely long period

occurring once every century or similarly long period (used especially in reference to celebratory games in ancient rome).

a secular priest.