Attending a meeting the holding of which is authorised by the authority or by a committee of the authority or by a joint committee of the authority and one or more other authorities.
Mynychu cyfarfod yr awdurdodir ei gynnal gan yr awdurdod neu gan un o bwyllgorau'r awdurdod neu gan un o gydbwyllgorau'r awdurdod ac un neu fwy o awdurdodau eraill.