big time

WordReference Random House Unabridged Dictionary of American English © 2025

big′ time′, 

1. Informal Terms the highest or most important level in any profession or occupation:
   She's a talented violinist, but she's not ready for the big time.
2. Slang Terms a very good time.
3. Show Business [Theat.] (in vaudeville) any highly successful circuit of theaters that produces two performances daily.
• 1860–65, American.
big′-time′, adj. 
big′-tim′er, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

big time noun

1. the big time ⇒ the highest or most profitable level of an occupation or profession, esp the entertainment business
2. (as modifier): a big-time comedian

ˈbig-ˈtimer noun