1.Definition: a horse used to set the pace in racing

Related Noun(s):pacer, pacesetter

Category: Animals

2.Definition: a leading instance in its field

Related Noun(s):pacesetter

Category: General

3.Definition: a specialized bit of heart tissue that controls the heartbeat

Category: General

4.Definition: an implanted electronic device that takes over the function of the natural cardiac pacemaker

Category: Objects