measure, ten to, unit of volume, about 180 liters
斛 centers on a specific unit of measurement for volume, historically about 180 liters, and by extension the act of measuring itself.
斛 combines 角 (horn, used as a measuring vessel) with 斗 (a dipper or measuring scoop), together representing a specific unit of volume.
A horn-shaped vessel 角 and a dipper 斗 come together to measure out exactly one 斛 of grain.
For コク, imagine a cook measuring 180 liters of broth with a giant horn and dipper: cook -> コク.