(1):

(v. t.) To render larger, more extended, or more intense, and the like; - used especially of telescopes, microscopes, etc.

(2):

(v. t.) To enlarge by addition or discussion; to treat copiously by adding particulars, illustrations, etc.; to expand; to make much of.

(3):

(v. i.) To become larger.

(4):

(v. i.) To speak largely or copiously; to be diffuse in argument or description; to dilate; to expatiate; - often with on or upon.