in a while
Also, after a while. After a period of time, usually a moderately short time. For example, Go ahead, I'll be along in a while, or After a while we turned off the television and went for a walk. [c. 1300]
What’s The Difference Between “A While” And “Awhile”Few word pairs capture the idiosyncrasies ("peculiar characteristics") of the English language like a while and awhile do.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.