timekeeper vs ticker

timekeeper and ticker both are nouns.

Word	Noun	Adjective	Verb	Adverb
timekeeper	Yes	No	No	No
ticker	Yes	No	No	No

As nouns, ticker is a hyponym of timekeeper; that is, ticker is a word with a more specific, narrower meaning than timekeeper:

Other hyponyms of timekeeper include atomic clock, clock, sandglass, sundial, timer, watch.

timekeeper (noun)	ticker (noun)
a measuring instrument or device for keeping time	a character printer that automatically prints stock quotations on ticker tape
a clerk who keeps track of the hours worked by employees	a small portable timepiece
(sports) an official who keeps track of the time elapsed	the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body