Definitions

1. conjunction

used to indicate a condition or exception, especially one that prevents something from being true or from happening

“I’ll go to the party unless it rains.”

2. preposition

used to indicate a condition or exception, especially one that prevents something from being true or from happening

“I’ll do it unless you ask me not to.”

3. subordinating conjunction

used to introduce a clause that expresses a condition or exception

“I won’t go unless you’re going too.”

4. noun

a condition or exception

“there’s no unless in that rule.”