1. devices that reverse the direction of electric current in a motor or generator
Usage: electrical engineering
2. mathematical operators that measure how much two operations fail to commute
Usage: mathematics; physics

Examples

• The motor’s commutators were worn and needed replacement.
• Carbon brushes make contact with the commutators to complete the circuit.
• In quantum mechanics, commutators determine uncertainty relations.
• The commutator of two matrices is found by subtracting their products.
• Electric motors rely on commutators to maintain rotation.
• Students learned to calculate commutators in their physics class.