Lon"gi*tude (?), n. [F., fr. L. longitudo, fr.
longus long.]
1. Length; measure or distance along the longest line; -- distinguished from breadth or thickness; as, the longitude of a room; rare now, except in a humorous
sense. Sir H. Wotton.
The
longitude of their cloaks.
Sir.
W. Scott. Mine [shadow] spindling into longitude immense.
Cowper.
2. (Geog.) The arc or portion of the equator intersected between the meridian of a
given place and the meridian of some other place from which longitude is reckoned, as from Greenwich, England, or sometimes from the capital of a country,
as from Washington or Paris. The
longitude of a place is
expressed either in degrees or in time; as, that of New York is 74° or 4 h. 56 min. west of Greenwich.
3. (Astron.) The distance in degrees, reckoned from the vernal equinox, on the ecliptic, to a circle at right angles to the ecliptic passing through the heavenly body whose longitude is designated; as, the longitude of Capella is
79°.
Geocentric longitude (Astron.), the longitude of a heavenly
body as seen from the
earth. -- Heliocentric longitude, the longitude of a heavenly body, as seen
from the sun's center. -- Longitude stars, certain stars whose position is known, and the data in regard to which are used in observations for finding the longitude, as by lunar distances.
Hear it pronounced