A relative by marriage.
Of or pertaining to a function expressible as f(⃑x)=A⃑x+⃑b (where A is a linear transformation and ⃑b is a constant), which, regarded as a transformation, maps parallel lines to parallel lines and finite points to finite points.
Assigning finite values to finite quantities.
Of two materials, having mutual affinity.
To refine.
A relative by marriage (or through affinity).
Sometimes specifically a parent-in-law of one's child, for which the dedicated terms co-mother-in-law, co-father-in-law are rare.