1) Assumption 2) Conjecture or notion 3) Hypothesis 4) Possibility 5) Something that is supposed 6) Supposition 7) The act of supposing 8) Theory Found on https://www.crosswordclues.com/clue/supposal
Sup·pos'al noun The act of supposing; also, that which is supposed; supposition; opinion. Shak. « Interest, with a Jew, never proceeds but upon supposal , at least, of a firm and sufficient bottom.» South. Found on http://www.encyclo.co.uk/webster/S/246
Lewis' explanation for the Chronicles of Narnia. Suppose that God created a world and chose to become incarnate and die in that world as He truly did in ours. What might that world be like? Found on https://www.encyclo.co.uk/local/21573