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

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

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

“Compressing the sensor-to-shooter cycle is the defining trend of this war at the tactical level,” said Franz-Stefan Gady, a military analyst and founder of defense advisory firm Gady Consulting.

From The Wall Street Journal • Jun. 5, 2026

Badenoch took issue with Matt Goodwin's stress on ethnicity as the key factor in defining Englishness.

From BBC • Jun. 5, 2026

Since limits are logically airtight, by defining a derivative in terms of limits, it becomes airtight as well—and puts calculus on a solid foundation.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife