[{"Bold_text": "noun", "List Items": ["the practice or system of using certain conventional marks or characters in writing or printing in order to separate elements and make the meaning clear, as in ending a sentence or separating clauses.", "the act of punctuating .", "punctuation marks punctuation marks.", "Biology.the sudden or accelerated extinction of some species and emergence of others, occurring only in isolated periods, as set forth in the of punctuated equilibrium punctuated equilibrium."]}]