What's the meaning of the phrase 'Under wraps'?
A thing is 'under wraps' if it is concealed from public view, with only a few insiders being aware of it.
What's the origin of the phrase 'Under wraps'?
The commonplace literal meaning of something that is under wraps is that it is wrapped up. There might seem little else to say about this expression which might be thought not even to qualify as an idiomatic phrase. The meaning of 'under wraps' is similar to that of 'under your hat', however, the derivation of the two is very different.
In fact, 'under wraps' doesn't refer to concealment by wrapping, it is a horse-racing practice where a jockey slows down a horse by wrapping the reins around the hands, either to avoid tiring the horse or in order to conceal its true racing ability.
The expression has something in common with another horse-racing term, in that it that it is widely misunderstood but also relates to trickery - 'dead ringer'.
The expression 'under wraps' was explained by G. Clark Cummings in the December 1956 issue of American Speech:
Jockey Ted Atkinson wrote me the following:
"The phrase breezed under wraps simply means breezed [exercised] under more than ordinary restraint - double wraps is also used..."
The Blood Horse (a weekly magazine devoted to the turf) in its issue of March 11, 1955, stated that the term under wraps was generally used 'in a literal sense to indicate that the rider had wrapped his reins around his hands in order to obtain sufficient purchase on the leader to restrain the horse from full speed.'
The Chicago Tribune, May 1893, contains an early use of 'under wraps' in print, which relates to a story of a horse being held back 'under wraps' in a race until the right moment:
...those who played [bet on] the brown colt on Keen's own statement... that he was the fastest and quickest to move he had ever trained, got nervous. But they had no reason to fear. Taral had the colt under wraps, and as the horses swung into the stretch with Despot in front he cut loose.
Of course, it is possible that this horse-racing usage of 'under wraps' derived independently from the literal 'concealed under wrapping' meaning, but it seems unlikely.