bowling pin vs skittle

bowling pin and skittle both are nouns.

Word	Noun	Adjective	Verb	Adverb
bowling pin	Yes	No	No	No
skittle	Yes	No	Yes	No

As nouns, skittle is a hyponym of bowling pin; that is, skittle is a word with a more specific, narrower meaning than bowling pin:

bowling pin: a club-shaped wooden object used in bowling; set up in triangular groups of ten as the target
skittle: a bowling pin of the type used in playing ninepins or (in England) skittles

Other hyponyms of bowling pin include candlepin, duckpin, headpin, kingpin, ninepin, skittle pin, tenpin.

bowling pin (noun)	skittle (noun)
a club-shaped wooden object used in bowling; set up in triangular groups of ten as the target	a bowling pin of the type used in playing ninepins or (in England) skittles

bowling pin (verb)	skittle (verb)
	play skittles