locus

noun4

1. •
   A place or locality, especially a centre of activity or the scene of a crime.

   • The cafeteria was the locus of activity.
2. •
   A fixed position on a string of DNA or RNA, especially a chromosome, that may be occupied by one or more genes.
3. •
   The set of all points whose coordinates satisfy a given equation or condition.

   • A circle is the locus of points from which the distance to the center is a given value, the radius.
4. •
   [in the plural] A passage in writing, especially in a collection of ancient sacred writings arranged according to a theme.