/lon"ji toohd', -tyoohd'/ , n.
1. Geog. angular distance east or west on the earth's surface, measured by the angle contained between the meridian of a particular place and some prime meridian, as that of Greenwich, England, and expressed either in degrees or by some corresponding difference in time.
2. Astron.
a. See celestial longitude .
b. See galactic longitude .
[ 1350-1400; ME longitudo length. See LONGI-, -TUDE ]