Synonyms for Exposit:

n.

exposit (noun)
expand, expound, enlarge, dilate, elaborate, lucubrate, flesh out, expatiate.

v.

communication (verb)
expound.

Other synonyms:

n.
dilate, elaborate, enlarge, expand, expatiate, expound, flesh out, lucubrate.
v.
elaborate, enlarge, expand, expatiate, expound, flesh out, lucubrate.
Other relevant words:
dilate.