Synodic; Synodical

Part of speech: adjective (a.)

1. Of or pertaining to a synod; transacted in, or authorized by, a synod; as, synodical proceedings or forms. "A synodical epistle." Bp. Stillingfleet.

2. Pertaining to conjunction, especially to the period between two successive conjunctions; extending from one conjunction, as of the moon or a planet with the sun, to the next; as, a synodical month (see Lunar month, under Month); the synodical revolution of the moon or a planet.