a field day

a field day

The freedom or an opportunity to do a lot of something one wants. (Often, news outlets are said to be "having a field day" if they are criticizing someone.) The press is going to have a field day if this story gets out. Our team has been having a field day going over all the information the study produced.
See also: field
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

field day

A time of great pleasure, activity, or opportunity, as in The press had a field day with this sensational murder trial. This colloquial expression, dating from the 1700s, originally referred to a day set aside for military maneuvers and exercises, and later was extended to a similar day for sports and games. Since the early 1800s it has been used more loosely.
See also: field
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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References in periodicals archive ?
Spies who want to check out faraway military camps, say, should soon have a field day with the world's first private spy satellite camera.