an explanation of the meaning of a word or phrase, especially in a dictionary

What's your definition of happiness?

a broad/narrow definition of the concept

There is no agreed definition of what a comprehensive school should be.

the act of saying what a word or an idea means

The term ‘partner’ requires careful definition.

Neighbours by definition live close by .

the quality of being clear and easy to see; the ability of a device to give clear images

The clarity and definition of the images are excellent.

The definition of this TV is very good.

LEARNit Dictionary