separatrix

noun, plural sep·a·ra·tri·ces [sep-uh–rey-tri-seez, -er-uh–trahy-seez] /ˌsɛp əˈreɪ trɪˌsiz, -ər əˈtraɪ siz/, sep·a·ra·trix·es.

1. something that divides or separates, as the line between light and dark areas on a partially illuminated surface.
2. virgule.
3. Mathematics. one of several symbols for separating components of a number, as a decimal point or comma.

noun plural separatrices (ˌsɛpəˈreɪtrɪˌsiːz)

1. another name for solidus (def. 1)

n.line or hooked line used to separate printed figures, originally with numerals and used where modern texts use a decimal point, also in other specialized senses, from Late Latin (linea) separatrix, feminine agent noun from separare (see separate (v.)).