dimidiation

Demonstrations of heraldic dimidiation. The one on the right shows how the result could be unrecognizable (hence quartering became preferred).

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

• (Received Pronunciation) enPR: dĭmĭ'dĭāʹshən, dīmĭ'dĭāʹshən, IPA^(key): /dɪˌmɪdɪˈeɪʃən/, /daɪˌmɪdɪˈeɪʃən/

dimidiation (countable and uncountable, plural dimidiations)

1. The act of dividing into halves.
2. The condition of being divided into halves.
3. (heraldry) 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.

• impalement

• Dimidiation on Wikipedia.Wikipedia