(1):

(a.) Enlarged or magnified; - said of images or of photographic pictures, etc.

(2):

(a.) Large enough to be seen; - said of the larger structural features and components of rocks which do not require the use of the microscope to be perceived. Opposed to microscopic.

(3):

(a.) Of or pertaining to the megascope or the projection upon a screen of images of opaque objects.