Meaning of “imperial” - Learner’s Dictionary

imperial

adjective uk us /ɪmˈpɪəriəl/
RULE [ always before noun ]

relating or belonging to an empire (= group of countries ruled by one person or government) or the person who rules it:

imperial rule
the imperial family
MEASURE

The imperial system of measurement uses units based on measurements such as inches, pints, and ounces.

(Definition of “imperial” from the Cambridge Learner’s Dictionary © Cambridge University Press)