early 15c., "to copulate" (of wolves, dogs), literally "to range (things) in a line," from Old French alignier "set, lay in line" (Modern French aligner), from à "to" (see ad-) + lignier "to line," from Latin lineare "reduce to a straight line," from linea (see line (n.)). Transitive or reflexive sense of "to fall into line" is from 1853. International political sense is attested from 1934. The French spelling with -g- is unetymological, and aline was an early form in English. Related: Aligned; aligning.
early 15c., liniament, "distinctive feature of the body, outline," from Latin lineamentum "contour, outline; a feature," literally "a line, stroke, mark," from lineare "to reduce to a straight line" (here apparently in an unrecorded sense "trace lines"), from linea "string, thread, line" (see line (n.)). Figurative sense of "a characteristic" is attested from 1630s.