defining

American  

[dih-fahy-ning] / dɪˈfaɪ nɪŋ /

adjective

1. decisive; critically important.

   Taking a course in architecture was a defining turn in her life.

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Other Word Forms

Derived Forms

• self-defining
  adjective
• nondefining
  adjective

Explanation

Something defining is essential to what something is. A defining moment in your life helps makes you what you are. In the dictionary, definitions tell you what words mean, and the similar word defining has to do with what things are too. The defining characteristic of a chair is that you sit on it. The defining feature of food is you can eat it. People have defining features too: if you went to a summer camp and had an amazing time, it could be a defining time in your life. Defining things helps shape and mold us.

Example Sentences

By defining these perceptual attributes more rigorously, the researchers have supplied a missing piece in Schrödinger's long standing vision for a closed mathematical model of color.

From Science Daily • Jun. 7, 2026

In the 1920s, Schrödinger built on that idea by defining hue, saturation, and lightness within a Riemannian model of color perception, using a metric that describes how people perceive color differences.

From Science Daily • Jun. 7, 2026

Yet audiences in the thousands were turning up nightly to see Gibbard reanimate the peak-millennial classics that made him one of indie rock’s defining stars.

From Los Angeles Times • Jun. 5, 2026

Carney has described AI as the defining technology of the era, one that already is changing how people work, learn and connect.

From The Wall Street Journal • Jun. 4, 2026

Her niceness is writ large, it is her defining quality and she needs it acknowledged, often, daily almost, which can be tiring.

From "The Girl on the Train" by Paula Hawkins