Dictionaries
Article I, Section 9, clause 2
The Privilege of the Writ of Habeas Corpus shall not be suspended unless when in Cases of Rebellion or Invasion the public Safety may require it



A Compendious Dictionary of the English Language (1806)
(Noah Webster 1806)
Rebellion     n. opposition to lawful authority



An American Dictionary of the English Language (1828)
www.WebstersDictionary1828.com
(Noah Webster 1828)
Rebellion
REBEL'LION, noun [Latin rebellio. among the Romans, rebellion was originally a revolt or open resistance to their government by nations that had been subdued in war. It was a renewed war.]

1. An open and avowed renunciation of the authority of the government to which one owes allegiance; or the taking of arms traitorously to resist the authority of lawful government; revolt. rebellion differs from insurrection and from mutiny. Insurrection may be a rising in opposition to a particular act or law, without a design to renounce wholly all subjection to the government. Insurrection may be, but is not necessarily, rebellion Mutiny is an insurrection of soldiers or seamen against the authority of their officers.

No sooner is the standard of rebellion displayed, than men of desperate principles resort to it.

2. Open resistance to lawful authority.

Commission of rebellion in law, a commission awarded against a person who treats the king's authority with contempt, in not obeying his proclamation according to his allegiance, and refusing to attend his sovereign when required; in which case, four commissioners are ordered to attach him wherever he may be found.


Merriam-Webster Dictionary (Online)
(Merriam-Webster 2024)