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

• nondefining adjective
• self-defining 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

While the 1970s were the defining decade for the Krofft brothers, they got their start as puppeteers decades prior.

From Los Angeles Times • Apr. 13, 2026

Over the past year, the Epstein files have metastasized into a defining symbol of elite impunity.

From Salon • Apr. 13, 2026

With Villa entering a defining period of the season - chasing their first trophy in 30 years and a return to the Champions League - Unai Emery knows his striker must continue to deliver.

From BBC • Apr. 9, 2026

“The Handmaid’s Tale,” once a defining show of the late 2010s, continued after extended pauses but struggled to maintain the cultural grip it once held.

From Los Angeles Times • Apr. 9, 2026

Its emergence was accompanied by the development of a new stone tool technology, now recognised as a defining feature of this species.

From "Sapiens: A Brief History of Humankind" by Yuval Noah Harari