‘Things standing thus’, provided that conditions have not changed; especially (International Law) the principle that a treaty is subject to an implied condition that if circumstances are substantially different from those obtaining when it was concluded, then a party to the treaty is entitled to be released from it. Also as adjective, designating such a clause or condition, and occasionally as noun, denoting this principle.
Late 16th century; earliest use found in Richard Bancroft (bap. 1544, d. 1610), archbishop of Canterbury. From post-classical Latin rebus sic stantibus things standing thus, provided that conditions have not changed from classical Latin rēbus, ablative plural of rēs thing + sīc so, thus + stantibus, ablative plural of stāns, present participle of stāre to stand.