Meaning of AMPLITUDE in English
( n. )
The arc of the horizon between the true east or west point and the center of the sun, or a star, at its rising or setting. At the rising, the amplitude is eastern or ortive: at the setting, it is western, occiduous, or occasive. It is also northern or southern, when north or south of the equator.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012