HARD-AND-FAST Synonyms: 86 Similar and Opposite Words

hard-and-fast

adjective

ˌhärd-ᵊn-ˈfast

as in certain

having been established and usually not subject to change hard-and-fast rules that governed the corporate environment in those days included strictures regarding office dress that were rigidly enforced

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Antonyms & Near Antonyms

as in unchangeable

not capable of changing or being changed hard-and-fast beliefs that are the rock-solid foundation of their religion

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Antonyms & Near Antonyms

Example Sentences

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Recent Examples of hard-and-fast One hard-and-fast rule to live by in this case? —

Stacia Datskovska, Footwear News, 26 Jan. 2026 But even in the absence of hard-and-fast rules and guardrails on how AI can be used in schools, education policymakers identified a number of ethical concerns raised by the technology’s spread, including student safety, data privacy and negative impacts on student learning. —

Janice Mak, The Conversation, 22 Jan. 2026 Don’t miss Mardi Gras King Cake There’s a hard-and-fast rule in New Orleans. —

Jenny Adams, AFAR Media, 30 Dec. 2025 This was my hard-and-fast belief — up until the trailer for The Sheep Detectives was released on December 18. —

Fran Hoepfner, Vulture, 18 Dec. 2025 See All Example Sentences for hard-and-fast

Recent Examples of Synonyms for hard-and-fast

Adjective

Recently, the Urban Summit was instrumental in urging the Kansas City Council to approve an ordinance that banned the sale of mini liquor bottles in certain parts of the city.

— Freddrell Green, Kansas City Star, 7 June 2026
Everybody knows that there’ll be certain parts that are doing okay, but a large part of the society in North Korea is very poor.

— Andrew McNicol, CNN Money, 7 June 2026