A pulse which occurs twice with each heartbeat.
A pulse with a double beat, one heartbeat for two arterial pulsations, or a seemingly weak wave between the usual heartbeats. This weak wave should not be counted as a regular beat. It is indicative of low arterial tension and is noted in fevers.
A pulse where the rebound wave is more pronounced. This is observed when arterial tension is reduced, giving the sensation of a dual beat to the touch.