Meaning of separatrix | Babel Free

Definitions

1. The ⟨L⟩ or pipe ⟨|⟩ mark formerly used to divide integers from decimals.
   historical
2. Synonym of decimal point, which replaced such marks.
   obsolete
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.

Examples

“Therefore in writing of decimall parts let the separatrix be always used.”

CEFR level