"Beseech" is the word of choice for Jonas 1:14 in most pre-KJV translations including the Wycliffe of 1395 all the way through to the Douay Rheims and the AV. I'm sure one could link back to the Hebrew or Greek of the passage for their equivalent to the Vulgate quaesumus here.
Jon 1:14 Wherefore they cried unto the Lord, and said, We beseech thee, O Lord, We beseech thee, let us not perish for this mans life, and lay not upon us, innocent blood: for thou, O Lord, hast done as it pleased thee.
Exactly right, John! The Vulgate reads quaesumus
Jonas 1:14 LXX (Septuagint) καὶ ἀνεβόησαν πρὸς κύριον καὶ εἶπαν Μηδαμῶς
, κύριε, μὴ ἀπολώμεθα ἕνεκεν τῆς ψυχῆς τοῦ ἀνθρώπου τούτου, καὶ μὴ δῷς ἐφ᾽ ἡμᾶς αἷμα δίκαιον, ὅτι σύ, κύριε, ὃν τρόπον ἐβούλου πεποίηκας.
Jonas 1:14 (Clementine Vulgate) Et clamaverunt ad Dominum, et dixerunt : Quæsumus
, Domine, ne pereamus in anima viri istius, et ne des super nos sanguinem innocentem : quia tu, Domine, sicut voluisti, fecisti.
Jonah 1:14 (Nova Vulgata) et clamaverunt ad Dominum et dixerunt quaesumus
Domine ne pereamus in anima viri istius et ne des super nos sanguinem innocentem quia tu Domine sicut voluisti fecistiquaesumus
and Μηδαμῶς are not even the same part of speech. Μηδαμῶς is the adverbial form of μηδαμός, which is an adjectival form of "no one" or "nobody". I do not know why Jerome and redactors substituted quaesumus
, unless the LXX and the Hebrew recensions of late antiquity disagreed. Perhaps "Jerome" went with a Latin word that corresponded better with the Hebrew. Nevertheless, there is little or no resemblance between the Greek and Latin at first glance. Perhaps Μηδαμῶς has an idiomatic meaning similar to quaesumus
. I don't have a septuagintal lexicon at home, so I don't know at the moment if this could be the case.