locus

noun

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

   “The cafeteria was the locus of activity.”

2. 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.”

3. A fixed position on a string of DNA or RNA, especially a chromosome, that may be occupied by one or more genes.

   “Holonyms: subband < band < region < replicon”

   “Meronyms: sublocus; gene, cistron; pseudogene”

4. (in-plural)A passage in writing, especially in a collection of ancient sacred writings arranged according to a theme.