'Principal' in the Bible

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

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 Yahweh lays waste their pasture.