Meaning of RESTRICTIVE CLAUSE in English

RESTRICTIVE CLAUSE

noun Date: circa 1895 a descriptive clause that is essential to the definiteness of the word it modifies (as that you ordered in “the book that you ordered is out of print”)

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.