Synodic
SYNOD'IC
SYNOD'ICAL, adjective Pertaining to a synod; transacted in a synod; as synodical proceedings or forms; a synodical epistle.
Synodical month, in astronomy, is the period from one conjunction of the moon with the sun to another. This is called also a lunation, because in the course of it the moon exhibits all its phases. This month consists of 29 days, 12 hours, 44 minutes, 3 seconds and 11 thirds.