1Characterized by or involving the clicking of heels together or against the floor, typically as part of a dance or as a gesture of exuberance; (hence) exuberant, energized.

2That brings the heels of one's boots or shoes quickly togethery while in a formal standing posture, so as to produce a sharp clicking noise, as a gesture of military discipline, obedience, or respect; characterized by such a clicking of heels; (in extended use) characterized by military discipline, obedience, or efficiency generally.