Dictionary

separatrix en · NOUN

Pronunciation

• /sɛpəˈɹeɪtɹɪks/

Etymology

Learned borrowing from Latin sēparātrīx, the feminine form of separator (originally owing to an implied līnea (“line”)), from sēparāre (“to divide; to separate”) + -trix (forming female agents). By surface analysis, separate + -trix. First developed as a decimal mark among the medieval Arab mathematicians, whence a shorter variant gave rise to the decimal comma employed by many European countries and their former colonies.

Meanings

1. (historical) The ⟨L⟩ or pipe ⟨|⟩ mark formerly used to divide integers from decimals.
   • Therefore in writing of decimall parts let the separatrix be always used. 1660, Jonas Moore, Moor's Arithmetick, page 13:
2. (obsolete) Synonym of decimal point, which replaced such marks.
3. 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.
4. A terminator: a line on a partially-illuminated surface separating the lit and shaded regions.
5. The line between regions having different magnetic fields.
6. The boundary separating two modes of behavior in a differential equation.

Forms

Coordinates

decimal point[Appendix:Glossary · decimal comma

Hypernyms

point · mark · decimal mark · character · radix point · separator

Synonyms

which replaced such marks · pipe · decimal point · slash