of, consisting of, or using lines

linear design.

pertaining to or represented by lines

linear dimensions.

extended or arranged in a line

a linear series.

involving measurement in one dimension only; pertaining to length

linear measure.

of or pertaining to the characteristics of a work of art in which forms and rhythms are defined chiefly in terms of line.

having the form of or resembling a line

linear nebulae.

Mathematics .

consisting of, involving, or describable by terms of the first degree.

having the same effect on a sum as on each of the summands

a linear operation.

Electronics . delivering an output that is directly proportional to the input

a linear circuit; a linear amplifier.

threadlike; narrow and elongated

a linear leaf.