PLAN'ETARY, adjective Pertaining to the planets; as planetary inhabitants; planetary motions.

1. Consisting of planets; as a planetary system.

2. Under the dominion or influence of a planet; as a planetary hour. [Astrology.]

3. Produced by planets; as planetary plague or influence.

4. Having the nature of a planet; erratic or revolving.

Planetary days, the days of the week as shared among the planets, each having its day, as we name the days of the week after the planets.