having sworn to tell the truth, usually with one's hand on the Bible
See full dictionary entry for oath
Examples of 'on oath' in a sentence
on oath
Before Franc, oise, I would have testified on oath that love on first sight is impossible.
Baxter, Stephen ANTI-ICE
Witnesses for the prosecution testified on oath; those for the defence did not.
The Times Literary Supplement (2014)
The police superintendent gave evidence on oath in support of the application.
Times, Sunday Times (2007)
On oath, when push comes to shove.
Times, Sunday Times (2018)
On oath in court, they told conflicting stories.
Times, Sunday Times (2009)
Officers stated on oath he saved their lives.
The Sun (2006)
Cops believe it cannot be proved he deliberately lied on oath.
The Sun (2008)
Perjury, which must be proved 'beyond reasonable doubt', entails knowingly giving false evidence on oath.
Times, Sunday Times (2007)
In the most modest magistrates' court in the land, witnesses to even minor misdemeanours are required to swear on oath or affirm before giving evidence.