This is the 14153rd most frequent Russian word.
определению
"By definition" or "to the definition."
Here, "определению" is used to introduce a standard definition or concept.
По определению, демократия — это форма правления, в которой власть принадлежит народу.
By definition, democracy is a form of government where power belongs to the people.
In this sentence, "определению" refers to a specific outcome of determining or defining something.
Мы пришли к этому определению через детальное обсуждение темы.
We arrived at this definition through a detailed discussion of the topic.
Here, "определению" is used in the context of defining or identifying something specific, such as a task.