alligation

al·li·ga·tion

noun \ˌal-ə-ˈgā-shən\

Definition of ALLIGATION

: a process or rule for the solution of problems concerning the compounding or mixing of ingredients differing in price or quality: a : one applied when a definite mixture is required—called also alligation alternate b : one applied when the price or quality of the mixture is to be determined—called also alligation medial