The definition of card-carrying is someone who is openly loyal to an organization or group.
Someone who manages a union is an example of card-carrying.
- owning a membership card in a specified organization
- Informal thorough, genuine, etc.: a card-carrying pacifist
- Being an enrolled member of a particular organization: a card-carrying Communist.
- Avidly devoted to a group or cause: card-carrying fitness enthusiasts.
Origin of card-carryingFrom the assumption that such a person carries a membership card