The line separating the illuminated from the dark portion of the moon's disc.
termĭnātor, ōris, m. [termino], he who limits , sets bounds , Aug. Civ. Dei, 4, 11. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
·noun One who, or that which, terminates. II. Terminator ·noun The dividing line between the illumi...
Webster's Dictionary of the English Language