rectilineal vs linear

rectilineal and linear both are adjectives.

Word	Noun	Adjective	Verb	Adverb
rectilineal	No	Yes	No	No
linear	No	Yes	No	No

rectilineal (adjective)	linear (adjective)
characterized by a straight line or lines	of or in or along or relating to a line; involving or having a single dimension
	designating or involving an equation whose terms are of the first degree
	of a circuit or device having an output that is proportional to the input
	measured lengthwise
	(of a leaf shape) long and narrow