Adjective

1. Assigning finite values to finite quantities.
2. Describing a function expressible as $f(\backslash vec\; x)=\; A\; \backslash vec\; x\; +\; \backslash vec\; b$ (which is not linear, but is similar).
3. Of or pertaining to a transformation that maps parallel lines to parallel lines and finite points to finite points.
4. Having mutual affinity, of two materials.

Verb

Adjective

1. similar
2. cognate
3. related, akin
4. affine