linear

adjective

1. of or relating to a line or lines
2. made of or using lines: linear design
3. in relation to length only; extended in a line
4. designating or of a style of art in which forms are sharply delineated and line is emphasized over color, light and shadow, etc.
5. having an effect or giving a response directly proportional to stimulus, force, or input: used esp. of electronic devices
6. easy to comprehend because of being logical and not complex
7. narrow and uniform in width, as the leaves of grasses
8. Chem. having the basic structure of a straight chain
9. Math. of or involving terms of a linear equation