Definition of: synodical

(si·nod′i·kəl) adjective
1. Of, pertaining to, or of the nature of a synod; transacted in a synod.
2. Astron. Pertaining to the conjunction of two heavenly bodies one of which revolves round the other, or to the interval between two successive conjunctions: a synodical month. Also syn·od·al (sin′ə·dəl), sy·nod′ic.
—sy·nod′·i·cal·ly adverb