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1. A systematic interpretation or explanation (usually written) of a specific topic
   - exposition

1. Add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
   - elaborate, lucubrate [archaic], expatiate, exposit, enlarge, flesh out, expand, dilate
    
2. State
   "expound one's reasons";
   - set forth, exposit

Derived forms: expoundings

Type of: clarify, clear up, elucidate, interpretation