(of fish) To form into, or travel in a school.

To educate, teach, or train (often, but not necessarily, in a school).

“Many future prime ministers were schooled in Eton.”

To defeat emphatically, to teach an opponent a harsh lesson.

To control, or compose, one's expression.

“She took care to school her expression, not giving away any of her feelings.”

Training or instruction.

Institutional education; attendance of school.

“I never let my schooling interfere with my education.”

The training of a horse at dressage.