— big-time , adj. — big-timer , n.
1. Informal. 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. a very good time.
3. Theat. (in vaudeville) any highly successful circuit of theaters that produces two performances daily.
[ 1860-65, Amer. ]