social studies any political party (= organization to get people elected) that is not as big or as influential as the two main parties

a person who is not one of the two main people involved in an argument or legal case

LAW a third person or organization less directly involved in an activity or in a legal case than the main people or organizations that are involved:

INSURANCE in an insurance contract, a person who is not the insurance company or the insured person, but who will receive money if they suffer loss or damage caused by the insured person:

LAW connected with a third person or organization less directly involved in an activity or in a legal case than the main people or organizations that are involved:

INSURANCE connected with insurance that will pay money to a person who suffers loss or damage caused by the insured person: