Semicolon definition: A semicolon is a punctuation mark that is used to separate equal grammatical units. What is a Semicolon? A semicolon is a type of punctuation mark. It is not end punctuation like a period, an exclamation point, or a question mark. Rather, a semicolon is used within a sentence. Semicolons look like a … Continue reading When to Use A Semicolon: How to Use A Semicolon