A Waxing gibbous is the gibbous moon after a new moon, and a waning gibbous is the gibbous moon after a full moon.he waxing phase of the moon is the period of time between new moon and full moon, where the size of the illuminated portion of the moon is increasing. The waning phase of t … he moon is the period of time between full moon and new moon, where the size of the illuminated portion of the moon is decreasing.