/ ˈpeɪsmeɪkə(r); NAmE / noun
1.
an electronic device that is put inside a person's body to help their heart beat regularly
2.
(also pace·setter especially in NAmE ) a person or an animal that begins a race quickly so that the other people taking part will try to copy the speed and run a fast race :
( figurative )
The big banks have been the pacesetters in developing the system.
3.
(also pace·setter especially in NAmE ) a person or team that is winning in a sports competition :
The local club are now only one point off the pacemakers.