say it: PAY-smay-kur
pacemaker is a noun meaning "a leading instance in its field". It carries 4 recorded senses.
a leading instance in its field
“the new policy will be a pacesetter in community relations”
a specialized bit of heart tissue that controls the heartbeat
an implanted electronic device that takes over the function of the natural cardiac pacemaker
a horse used to set the pace in racing
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for pacemaker come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.