linear

adjective

1. 1

   of a circuit or device having an output that is proportional to the input

   analogue device

   linear amplifier

2. 2

   of or in or along or relating to a line; involving a single dimension

   a linear measurement

3. 3

   designating or involving an equation whose terms are of the first degree

4. 4

   measured lengthwise

   cost of lumber per running foot

5. 5

   (of a leaf shape) long and narrow