whale of a time
A very enjoyable experience, as in We had a whale of a time in Puerto Rico. This idiom alludes to the largest mammal to describe something very large and impressive. [Colloquial; early 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.