Sa·bel·li·an·ism 
(sə-bĕlē-ə-nĭz′əm)
(sə-bĕlē-ə-nĭz′əm)n.
A version of Monarchianism holding that the Godhead is a single being, differentiated only into a succession of modes or operations.
[After Sabellius (fl. 3rd cent. AD), Monarchian theologian.]