take an oath

take an oath

To make a formal, binding promise (to do something). You took an oath when you agreed to be a witness in this trial, so you must answer my questions completely truthfully! We all took oaths to keep this a secret until the day we die.
See also: oath, take
Farlex Dictionary of Idioms.

take an oath

to make an oath; to swear to something. You must take an oath that you will never tell anyone about this. When I was a witness in court, I had to take an oath that I would tell the truth.
See also: oath, take
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

take an oath

To agree to a pledge of truthfulness or faithful performance.
See also: oath, take
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • on oath
  • on/under oath
  • Scout's honour
  • on one's honor
  • on (one's) honor
  • on honor
  • on (one's) honour
  • on your honour
  • be forsworn
  • have (one's)/the facts straight