'Served' in the Bible

So when the servants of Hadadezer saw that they were defeated by Israel, they made peace with David and served him. Thus the Arameans were not willing to help the sons of Ammon anymore.

But Nadab and Abihu died before their father and had no sons. So Eleazar and Ithamar served as priests.

Now this is the enumeration of the sons of Israel, the heads of fathers’ households, the commanders of thousands and of hundreds, and their officers who served the king in all the affairs of the divisions which came in and went out month by month throughout all the months of the year, each division numbering 24,000:

Now David assembled at Jerusalem all the officials of Israel, the princes of the tribes, and the commanders of the divisions that served the king, and the commanders of thousands, and the commanders of hundreds, and the overseers of all the property and livestock belonging to the king and his sons, with the officials and the mighty men, even all the valiant men.