SEPARATRIX

solidus, slash, virgule, diagonal, stroke, separatrix

(noun) a punctuation mark (/) used to separate related items of information

Source: WordNet® 3.1

Etymology

Noun

separatrix (plural separatrixes or separatrices)

(typography, historical) The ⟨L⟩ or pipe ⟨|⟩ mark formerly used to divide integers from decimals.

Synonyms: pipe, slash

(typography, obsolete) synonym of decimal point, which replaced such marks.

(typography) The proofreader's mark resembling a slash ⟨ / ⟩ or vertical bar ⟨ | ⟩ placed after a note in the margin to indicate that it should replace the item(s) struckthrough in the running text or to separate it from other margin notes.

A terminator: a line on a partially-illuminated surface separating the lit and shaded regions.

(physics) The line between regions having different magnetic fields.

(mathematics) The boundary separating two modes of behavior in a differential equation.

Source: Wiktionary

Sep`a*ra"trix, n.; pl. L. -trices, E. -trixes. Etym: [L., she that separates.] (Arith.)

Definition: The decimal point; the dot placed at the left of a decimal fraction, to separate it from the whole number which it follows. The term is sometimes also applied to other marks of separation.

Source: Webster’s Unabridged Dictionary 1913 Edition