Real Dictionary

linear
A linear process or development is one in which something changes or progresses straight from one stage to another, and has a starting point and an ending point.
a mutual or reciprocal relationship between two or more things [...]
a part of a railway, road, etc, that slopes upwards or downwards; inclination [...]
a representation, usually on a smaller scale, of a device, structure, etc [...]
formed or blended together by mixing [...]
general tendency or direction [...]
of, in, along, or relating to a line [...]
the adoption by an adult or adolescent of behaviour more appropriate to a child, esp as a defence mechanism to avoid anxiety [...]
the limits within which a person or thing can function effectively [...]