field day

WordReference Random House Learner's Dictionary of American English © 2025

ˈfield ˌday, n. [countable]

1. a day devoted to outdoor sports or athletic contests, such as at a school.
2. Military a day for military exercises and display.
3. an occasion or opportunity to enjoy or amuse oneself completely:
   The children had a field day with their new toys.

WordReference Random House Unabridged Dictionary of American English © 2025

field′ day′, 

1. a day devoted to outdoor sports or athletic contests, as at a school.
2. an outdoor gathering;
   outing;
   picnic.
3. Military a day for military exercises and display.
4. an occasion or opportunity for unrestricted activity, amusement, etc.:
   The children had a field day with their new skateboards.
• 1740–50

Collins Concise English Dictionary © HarperCollins Publishers::

field day noun

1. a day spent in some special outdoor activity, such as nature study or sport
2. a day devoted to manoeuvres or exercises, esp before an audience
3. a day or time of exciting or successful activity: the children had a field day with their new toys