in private; secretly
en privado; secretamente (en privado; secretamente)
"The deal was made behind closed doors."
"El trato se hizo a puerta cerrada." (El trato se hizo a puerta cerrada.)
to improve an existing product or idea
to change political allegiance or party
To be in a situation that is too difficult to understand or...
to become calmer after being angry or excited
to feel extremely nervous or anxious
extremely accurate and consistent performance