rule of thumb

noun phrase

1
: a method of procedure based on experience and common sense
2
: a general principle regarded as roughly correct but not intended to be scientifically accurate

Examples of rule of thumb in a Sentence

Recent Examples on the Web
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Broadly, the rule of thumb is to drink it during periods of intense competition (to allow for muscle recovery) while avoiding it during periods of training (to promote muscle development). Jacob Whitehead, New York Times, 8 Sep. 2026 Pausing midway through a meal to check in with your hunger is a good rule of thumb, and boxing half of a meal at a restaurant to bring home can also help. Gavin Escott, USA Today, 3 Sep. 2026 This is generally the rule of thumb for this time of year, and there hasn’t been anything particularly abnormal about this summer, Bonnette said. Brayden Garcia, Fort Worth Star-Telegram, 24 Aug. 2026 These two things are related in possibly smaller cartridge choice than the old rule of thumb or the old idea of what a bear-defense firearm should be. Alex Robinson, Outdoor Life, 20 Aug. 2026 See All Example Sentences for rule of thumb

Word History

First Known Use

circa 1658, in the meaning defined at sense 1

Time Traveler
The first known use of rule of thumb was circa 1658

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Cite this Entry

“Rule of thumb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rule%20of%20thumb. Accessed 10 Sep. 2026.

Kids Definition

rule of thumb

1
: a method based on experience and common sense
2
: a general principle that is roughly correct
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