Locus (?), n.; pl. Loci (#), & Loca (#). [L., place. Cf. Allow, Couch, Lieu, Local.] 1. A place; a locality.
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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.
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Plane locus, a locus that is a straight line, or a circle. -- Solid locus, a locus that is one of the conic sections.
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