Enter a clue or pattern or both:
The Clue
Explanatory essay (10 letter answer)
The Answer
COMMENTARY
Tags
Notes
The answer COMMENTARY is so rare that it appears less than once every 2500 puzzles.
Definition
COMMENTARY as a noun:
1. (comment, commentary) = a written explanation or criticism or illustration that is added to a book or other textual material; "he wrote an extended comment on the proposal"