The principal unit in the organization of the Fraternity is the college chapter.

The ecosystem is the principal unit of study in ecosystem ecology.

Initially the manor was the principal unit of local administration and justice in the early rural economy.

He was speaking about the new president chosen for the company's men's division, its principal unit.

The principal unit of state government is the municipality.

Operating income fell at four of the company's six principal units.

The principal unit of this force, the Medina garrison itself.

It is best known for its principal operating unit.

Heavy infantry: This was the principal unit of the legion.

Subsidiary components are items which are the major parts of a principal unit.