Of or pertaining to this present world, or to things not spiritual or holy; relating to temporal as distinguished from eternal interests; not immediately or primarily respecting the soul, but the body; worldly.

Not regular; not bound by monastic vows or rules; not confined to a monastery, or subject to the rules of a religious community; as, a secular priest.

Belonging to the laity; lay; not clerical.

A secular ecclesiastic, or one not bound by monastic rules.

Long term, not temporary or cyclical.

Pertaining to an age, or the progress of ages, or to a long period of time; accomplished in a long progress of time; as, secular inequality; the secular refrigeration of the globe.

Long-term time frame (10-50 years or more).

In astronomy, secular mean that a phenomenon takes a tremendous amount of time to unfold, and occurs gradually. Secular change, for example, is a long-standing, continuous (and nonperiodic) change to a system.