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

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of hard-and-fast 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 There’s no hard-and-fast rule, and if someone tells you there is? —

Natalie Krebs, Outdoor Life, 28 Aug. 2025 See All Example Sentences for hard-and-fast

Recent Examples of Synonyms for hard-and-fast

Adjective

Regulations require certain size hallways, for example, and heavy robotic equipment may need extra floor support and special elevators.

— Suzanne King, Kansas City Star, 2 May 2026
Recent polling suggests that roughly 30% of young Americans hold the view that political violence can be justified in certain circumstances.

— Andrew Cuomo, New York Daily News, 2 May 2026