/kon"jee euhs/ , n. , pl. congii /-jee uy'/ .
1. (in prescriptions) a gallon (3.7853 liters).
2. an ancient Roman unit of liquid measure equal to about 0.8 U.S. gallon (3.2 liters).
[ 1350-1400; ME konchíon, equiv. to kónch ( e ) CONCH + -ion dim. suffix ]