The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
or big-time Informaladjective
Significant or important; major: a bigtime comedian.adverb
To an extreme degree; very much: Sales are expanding, big-time.