allied · adjective /ˈæl.ɑɪd/Full view
C2 joined by a formal agreement
Dictionary example:

the allied powers

Learner example:

During the Second World War, he joined the US Navy and was then sent on a mission to Brazil with the aim of patrolling the coasts to avoid a German bombing [of] allied ships. (Certificate of Proficiency in English; C2; Portuguese)

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