dimidiation

Meanings

1. The act of dividing into halves.
2. The condition of being divided into halves.
3. A marshalling of two coats of arms by the bisection per pale of their escutcheons and forming a new coat of arms from the dexter half of one coat and the sinister half of the other.

Etymology

Continuing the Middle English dimydicion (circa 1425, in an arithmetical sense), from the Late Latin dīmidiātiō.