This is the 15645th most frequent Russian word.
прилагательное
Adjective.
Here, "прилагательное" is used as a noun to refer to a specific grammatical category in linguistics.
Это прилагательное очень длинное.
This adjective is very long.
In this instance, "прилагательное" signifies an item being selected and applied.
Я добавлю подходящее прилагательное в предложение.
I will add an appropriate adjective to the sentence.
Here, "прилагательное" is used to denote a linguistic term while providing an example.