Definitions

1. preposition

used to indicate the point or time at which something will happen or be done

“We won’t leave until the concert finishes.”

2. conjunction

used to introduce a clause or phrase expressing a condition or exception

“You can go to the party, but you must be home by midnight until the school year ends.”

3. verb

to continue doing or existing until a particular point or time

“She will work until she finds a better job.”