field day

plural field days

1. governmentA day for maneuvers and tactical exercises in the field (across the landscape).

   This morning I got up, with great difficulty, at 6.30, and at 7.45 we started out for a Brigade Field Day. Did an attack from 10.30 to 2.30, but it wasn't a strenuous one for me as I was told to "become a casualty" soon after the 3000 yard assault began ….

   1937, Siegfried Sassoon, Sherston's Progress, London: Faber, page 621 (in The Complete Memoirs of George Sherston )

2. USA school day for athletic events.

   Synonyms: sports day

3. A day of class taken away from school for a field trip.
4. idiomaticA great time or a great deal to do; a period of bustling activity.

   They went to the park and had a field day playing on the swings.

   1 more example

   A family of frisky squirrels was having a field day amongst the towering obstacle course of foliage.

   2014, Vance Munraff, Sounds Like Paradise: a Fugitive's Tale, Lulu.com, →ISBN, page 62

5. idiomaticA great time or a great deal to do, at somebody else's expense.

   The scandal was a field day for the press.

   5 more examples

   The reporters will have a field day with a comment like that.

   What a field day for the heat (Ooo-ooo-ooo) / A thousand people in the street (Ooo-ooo-ooo) / Singing songs and a-carryin' signs (Ooo-ooo-ooo) / Mostly say "Hooray for our side" (Ooo-ooo-ooo)

   1966 December, Stephen Stills, “For What It's Worth”performed by Buffalo Springfield

   It had become a legal nightmare. All parties had retained attorneys; the community and press were having a field day.

   2009, Julie Jurgens-Shimek, Autism Is a Four Letter Word: Love, AuthorHouse, →ISBN, page 32

   I thought I'd been so thorough, so efficient, and so cost conscious, but look where I was now. The devil was having a field day with my head.

   2012, Claudia Parker, Becoming a Mother, While Losing My Own, Xlibris Corporation, →ISBN, page 158

   The reporters were having a field day with our saga and the courtroom filled with spectators.

   2012, Gary Rosen, Unfair to Genius: The Strange and Litigious Career of Ira B. Arnstein, Oxford University Press, →ISBN, page 140

6. NavyUSspecificallyUS Coast Guard and US Marine CorpsgovernmentA day on which there is top-to-bottom all-hands cleaning.