Definition of in arms
- He and I were brothers in arms.
: a human upper limb
: something like or corresponding to an arm: such as
: the forelimb of a vertebrate
: to furnish or equip with weapons
: to furnish with something that strengthens or protects
: to equip or ready for action or operation
: a means (such as a weapon) of offense or defense
: a combat branch (as of an army)
: an organized branch of national defense (such as the navy)
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