(photography) An adjacency or border effect created during development, at the border between areas of high and low densities.

A kind of fishing line to which are attached several crosspieces of whalebone which carry a hook at each end.

(nautical) A line rove through a block at the jaws of a gaff; used to haul it down.

(mathematics) A topological space, constructed by stringing together an uncountable number of intervals, which is "longer" than the real line.

A connected series of measurements, by means of a level, along a given line, such as that of a railroad, to ascertain the profile of the ground.

(printing, historical) A thin piece of metal used to open the lines of type to a regular distance from each other, and for other purposes; a lead.

The depth to which the water present in the soil is expected to freeze in winter. / The depth to which the water present in the soil is actually frozen in a given place at a given point in time.

A cut through forest cleared to permit seismic survey.

A faunal boundary line that separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia.

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