Meaning of “double-barrelled” - Learner’s Dictionary

double-barrelled

adjective mainly UK (US double-barreled) uk us /ˌdʌblˈbærəld/
GUN

A double-barrelled gun has two of the cylindrical parts that bullets come out of.

NAME UK

A double-barrelled name is two names joined together.

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