Antonyms for unite

combine; join together:

divide, sever, disjoin, exclude, part, unmix, separate, dissociate, disassociate, divorce, disconnect.

social:

divide.

noun:

deconcentrate, alienate, fractionate, fall out, resolve, estrange, disengage, disaffiliate, isolate, scatter, section, decentralize, carve up, part, spread.