wristwatch vs ticker

wristwatch and ticker both are nouns.

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

As nouns, ticker is a hypernym of wristwatch; that is, ticker is a word with a broader meaning than wristwatch:

Other hypernyms of wristwatch include watch.

wristwatch (noun)	ticker (noun)
a watch that is worn strapped to the wrist	a character printer that automatically prints stock quotations on ticker tape
	a small portable timepiece
	the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body