ROGET THESAURUS
subdichotomy
bisection
N
bisection, bipartition, dichotomy,
subdichotomy, halving, dimidiation, bifurcation, forking, branching, ramification, divarication, fork, prong, fold, half, moiety, bisected, cloven, cleft, bipartite, biconjugate, bicuspid, bifid, bifurcous, bifurcate, bifurcated, distichous, dichotomous, furcular, semi-, demi-, hemi.