A party who makes or is bound by a covenant; one who promises or pledges under a solemn binding agreement.
From covenant plus the suffix -er (indicating the agent who performs the action), with capital C often used for the Scottish Covenanters of the 17th century.
The Scottish Covenanters were rebels who literally died rather than break their covenant—their conviction that a sworn oath transcended even the king's authority helped inspire modern ideas of individual conscience.
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