The Collaborative International Dictionary of English v.0.48:

Locus \Lo"cus\, n.; pl. Loci, & Loca. [L., place. Cf.
   Allow, Couch, Lieu, Local.]
   1. A place; a locality.
      [1913 Webster]

   2. (Math.) The line traced by a point which varies its
      position according to some determinate law; the surface
      described by a point or line that moves according to a
      given law.
      [1913 Webster]

   Plane locus, a locus that is a straight line, or a circle.


   Solid locus, a locus that is one of the conic sections.
      [1913 Webster]

WordNet (r) 3.0 (2006):

locus
    n 1: the scene of any event or action (especially the place of a
         meeting) [syn: venue, locale, locus]
    2: the specific site of a particular gene on its chromosome
    3: the set of all points or lines that satisfy or are determined
       by specific conditions; "the locus of points equidistant from
       a given point is a circle"

The Free On-line Dictionary of Computing (19 January 2023):

Locus

   A distributed system project supporting transparent access to
   data through a network-wide file system.