'Guardians' in the Bible

Now Ahab had seventy sons in Samaria. And Jehu wrote letters, and sent to Samaria, to the princes of Jizreel, to the elders, and to Ahab's guardians, saying,

And he that was over the house, and he that was over the city, and the elders, and the guardians sent to Jehu, saying, We are thy servants, and will do all that thou shalt bid us; we will not make any one king; do what is good in thy sight.

but he is under guardians and stewards until the period fixed by the father.