The word "hemisected" means to divide something into two equal halves. In contrast, the antonym for hemisected could be "whole." This word indicates that there is no division or cut in the object. Another antonym could be "unsplit," indicating that the object has not been separated into two parts. "Intact" is another antonym, which means that something is complete, undamaged, or unbroken. Other possible antonyms for hemisected include "unseparated," "un-parted," "undivided," and "unsegmented." These words have opposite meanings to hemisected and are useful when describing objects that are not divided into equal parts.