(anatomy) The line that divides the upper two thirds of the anal canal from the lower third. Developmentally, it represents the hindgut-proctodeum junction.

(meteorology) An imaginary line across a continent that separates moist air from an eastern body of water and dry desert air from the west.

plural of dry line

plural of red line

plural of line number

(computing) The sequential number indicating a particular line of text in a text file.

a line drawn (on a map) in a maritime area which marks the maritime boundary between two countries.

plural of timber line

plural of Plimsoll line

A navigator's observation of the Sun to determine latitude.