Term:

TRAFFIC ALERT AND COLLISION AVOIDANCE SYSTEM (TCAS)

Meaning: An airborne collision avoidance system based on radar beacon signals which operates independent of ground-based equipment. TCAS-I generates traffic advisories only. TCAS-II generates traffic advisories, and resolution (collision avoidance) advisories in the vertical plane.
Previous Term: TRAFFIC ALERT (aircraft call sign), TURN (left/right) IMMEDIATELY, (climb/descend) AND MAINTAIN (altitude)
Next Term: TRAFFIC IN SIGHT