A more thorough explanation:

Definition: A nonjuror is someone who refuses to pledge allegiance to the sovereign or breaks an oath to a monarch. In England and Scotland, a nonjuror was a clergyman who refused to recognize William of Orange as king after James II and his heirs and successors. In Scotland, a nonjuror was also a clergyman who refused to renounce the Episcopal Church when it was disestablished in 1690 in favor of Presbyterianism.

Example: John was called for jury duty but he did not show up. He is a nonjuror because he is not serving as a juror.

Example: After the Glorious Revolution in 1688, many clergymen in England and Scotland refused to break their oath to James II and his heirs and successors. They were called nonjurors and were not recognized by the government.

Explanation: The examples illustrate the two different meanings of nonjuror. The first example shows that a nonjuror is someone who is not serving as a juror. The second example shows that a nonjuror is someone who refuses to pledge allegiance to the sovereign or breaks an oath to a monarch. In this case, the nonjurors were clergymen who refused to recognize the new king after the Glorious Revolution.