swear(to state, declare, or promise solemnly with an oath, or very definitely and positively • The witness must swear to tell the truth; He swore an oath of loyalty; Swear never to reveal the secret; I could have sworn (= I'm sure) she was here a minute ago); vow(в чём-либо; to make a solemn promise (that); to threaten • He vowed that he would die rather than surrender; He vowed revenge on all his enemies); swear by(to appeal to (e.g. God) as a witness of one's words • I swear by Heaven that I'm innocent); oath; cross heart; give an oath; swear an oath; swear by(чем-либо, кем-либо); take dick; make an oath(Andrey Truhachev); vow and declare(Taras); curse; asseverate; swear to(to make a solemn statement, with an oath, in support of, в чём-л. • I'll swear to the truth of what he said; I think he was here this morning, but I wouldn't like to swear to it)
buff; swear by(кем-либо/чем-либо • A witness swore by the Bible that he would tell the truth. == Свидетель поклялся на библии, что будет говорить только правду.; Now we can be sure that Holdwin will come on time, since the commissar swears by him. == Теперь мы можем быть уверенными, что Холдуин придёт вовремя, коль сам комиссар поручился за него.)
wiktionary.org sea holly)