Definition of ortive in US English:

ortive

adjective

  • Astronomy. Of or relating to the rising of a celestial object. Usually in "ortive amplitude": the angular distance of an object at its rising measured from the eastern point of the horizon.

Origin

Mid 17th century; earliest use found in Henry Gellibrand (1597–1637), mathematician. From classical Latin ortīvus relating to rising (1st cent. a.d. in astronomical context) from ortus rising, rise + -īvus -ive.

Pronunciation

ortive

/ˈɔːtɪv/