An Etymological Dictionary of Astronomy and Astrophysics

1. The subject of a discourse or of one of its parts.
   

   2. The main and explicit subject matter of a literary work, often composed of several themes.

Etymology (EN): From L. topica, from Gk. topikos “pertaining to a common place, of a place,” from topos “a place.”

Etymology (PE): Bârak, from bâre “subject, matter, meaning,” as in dar bare-ye “in the matter of; about,” + nuance suffix -ak.