Merriam-Webster's Word of the Day for November 2, 2025 is:

arbitrary • \AHR-buh-trair-ee\  • adjective

Arbitrary describes something that is not planned or chosen for a particular reason, is not based on reason or evidence, or is done without concern for what is fair or right.

// Because the committee wasn’t transparent about the selection process, the results of the process appeared to be wholly arbitrary.

// An arbitrary number will be assigned to each participant.

See the entry >

Examples:

“The authority of the crown, contemporaries believed, was instituted by God to rule the kingdom and its people. England’s sovereign was required to be both a warrior and a judge, to protect the realm from external attack and internal anarchy. To depose the king, therefore, was to risk everything—worldly security and immortal soul—by challenging the order of God’s creation. Such devastatingly radical action could never be justified unless kingship became tyranny: rule by arbitrary will rather than law, threatening the interests of kingdom and people instead of defending them.” — Helen Castor, The Eagle and the Hart: The Tragedy of Richard II and Henry IV, 2024

Did you know?

Donning black robes and a powdered wig to learn about arbitrary might seem to be an arbitrary—that is, random or capricious—choice, but it would in fact jibe with the word’s etymology. Arbitrary comes from the Latin noun arbiter, which means “judge” and is the source of the English word arbiter, also meaning “judge.” In English, arbitrary first meant “depending upon choice or discretion” and was specifically used to indicate the sort of decision (as for punishment) left up to the expert determination of a judge rather than defined by law. Today, it can also be used for anything determined by or as if by chance or whim.