(astronomy, geology) Any long marking, dark or bright, on a planet or moon's surface.

plural of linea

A dark vertical line, running up the abdomen from the pubis to the navel (though it sometimes runs further, to the top of the abdomen) that forms during pregnancy.

(anatomy) A fibrous structure that runs down the midline of the abdomen in humans and other vertebrates.

plural of recurrent slope linea

(aerology, aerography, planetology) An ephemeral dark linear feature found on slopes that recurs seasonally.

Having the form of a line; straight or roughly straight; following a direct course. / Of or relating to lines. / Made, or designed to be used, in a step-by-step, sequential manner.

(radio slang) Ellipsis of linear amplifier..

Descent in a line from a common progenitor; progeny; descending line of offspring or ascending line of parentage. / (advertising) A number of lines of text in a column.

(astronomy) A comet, cataloged as “C/1999 S4”, discovered on September 27, 1999, by the Lincoln Near-Earth Asteroid Research program in New Mexico. (See https://web.archive.org/web/20051220100856/http://www.windows.ucar.edu/tour/link=/comets/linear.html) Sometimes spelled LINEAR.