'Principal' in the Bible

Wail, ye shepherds, and cry; and wallow in ashes , ye principal of the flock; for the days of your slaughter and of your dispersions are fully come, and ye shall fall like a goodly vessel.

And the shepherds shall have no way to flee, nor the principal of the flock to escape.

A voice of the cry of the shepherds, and the wailing of the principal of the flock! for Jehovah layeth waste their pasture.