dimidiation
noun
di·mid·i·a·tion
-ˌmidēˈāshən
plural -s
: a formation of marshaling by joining the dexter half of one heraldic shield with the sinister half of another divided per pale or sometimes per bend
Word History
Etymology
Late Latin dimidiation-, dimidiatio action of halving, from Latin dimidiatus + -ion-, -io -ion