Nouns

(n)dividea serious disagreement between two groups of people (typically producing tension or hostility)
(n)watershed, water parting, dividea ridge of land that separates two adjacent river systems

Verbs

(v)divide, split, split up, separate, dissever, carve upseparate into parts or portions“divide the cake into three equal parts”, “The British carved up the Ottoman Empire after World War I”
(v)divide, fractionperform a division“Can you divide 49 by seven?”
(v)separate, divideact as a barrier between; stand between“The mountain range divides the two countries”
(v)separate, divide, partmove or break apart“The two pieces that we had glued separated”
(v)separate, dividemake a division or separation
(v)separate, disunite, divide, partforce, take, or pull apart“He separated the fighting children”, “Moses parted the Red Sea”