on under oath イディオム
take oath
say that something is true, give my word of honor He took an oath that he is the child's father. I believe him.
take oath|oath|take
v. phr. To promise to tell the truth or to do some task honestly, calling on God or some person or thing as a witness. Mary took her oath that she did not steal the watch. John took oath that he would fill the office of president faithfully.
loath
loath
nothing loath
not reluctant(ly); willing(ly)
oath
oath
1.
take oath
to promise or declare by making an oath; swear solemnly
2.
under oath
bound or obligated by having made a formal oath, as in a court of law