Linea reeta
Defined in 1 dictionary — Black's (1910)
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
The direct line ; the vertical line. In computing degrees of kindred and the succession to estates, this term denotes the direct line of ascendants and descendants. Where a person springs from another immediately, or mediately through a third person, they are said to be in the direct line, (linea reeta,) and are calied "ascendants" and "descendants." Mackeld. Rom. Law, § 129.
Defined under Linea in Black's Law Dictionary.