guideline

American  

[gahyd-lahyn] / ˈgaɪdˌlaɪn /

noun

1. any guide or indication of a future course of action.

   guidelines on the government's future policy.

2. a lightly marked line used as a guide, as in composing a drawing, a typed page, or a line of lettering.

3. a rope or cord that serves to guide one's steps, especially over rocky terrain, through underground passages, etc.

4. a rope or wire used in guiding the movement of stage scenery or curtains being raised or lowered.

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guideline British  

/ ˈɡaɪdˌlaɪn /

noun

1. a principle put forward to set standards or determine a course of action

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Etymology

Origin of guideline

An Americanism dating back to 1775–85; guide + line ¹

Explanation

A guideline is a rule-of-thumb or suggestion that shows or tells you how to behave. If you want to stay healthy, you might want to follow the government's dietary guidelines. Sample guideline: go easy on the salt. In the 18th century, guideline referred to an actual line that you drew on fabric before cutting. So for example, if you wanted to cut a piece of linen to make a dress, you'd draw a guideline on it first to make sure the incision would be straight. The line guided your cut; over time, the word became a metaphor for a guide to any sort of action.

Example Sentences

The economists considered a family earning between five times and 15 times the poverty guideline to be in the upper middle class—thus their parameters of $133,000 to $400,000.

From The Wall Street Journal • Apr. 5, 2026

In addition to statins, the guideline includes updated recommendations on other cholesterol-lowering therapies, including ezetimibe, bempedoic acid, and injectable PCSK9 monoclonal antibodies.

From Science Daily • Mar. 29, 2026

No major guideline recommends measuring endogenous GLP-1 levels before initiating treatment.

From Slate • Mar. 22, 2026

And the daily average of PM10 particle levels reached 128.3 micrograms per cubic meter in Elbistan last year -- over eight times the WHO guideline of 15 micrograms.

From Barron's • Feb. 19, 2026

According to this guideline, like may be used only for resemblance to an exemplar, as in I’ll find someone like you and Poems are made by fools like me.

From "The Sense of Style" by Steven Pinker

Related Words

• code
• ground rule
• guidance
• instruction
• protocol
• rule