'Third' in the Bible

On the third day a man came [unexpectedly] from Saul’s camp with his clothes torn and dust on his head [as in mourning]. When he came to David, he bowed to the ground and lay himself face down [in an act of great respect and submission].

his second, Chileab, by Abigail the widow of Nabal of Carmel; the third, Absalom the son of [his wife] Maacah, daughter of Talmai the king of Geshur;

Then David sent the army out, a third under the command of Joab, a third under Abishai the son of Zeruiah, Joab’s brother, and a third under the command of Ittai the Gittite. And the king said to the men, “I myself will certainly go out [to fight] with you.”