ruler vs yard measure

ruler and yard measure both are nouns.

Word	Noun	Adjective	Verb	Adverb
ruler	Yes	No	No	No
yard measure	Yes	No	No	No

As nouns, yard measure is a hyponym of ruler; that is, yard measure is a word with a more specific, narrower meaning than ruler:

ruler: measuring stick consisting of a strip of wood or metal or plastic with a straight edge that is used for drawing straight lines and measuring lengths
yard measure: a ruler or tape that is three feet long

Other hyponyms of ruler include carpenter's rule, foot rule, meterstick, metrestick, yardstick.

ruler (noun)	yard measure (noun)
measuring stick consisting of a strip of wood or metal or plastic with a straight edge that is used for drawing straight lines and measuring lengths	a ruler or tape that is three feet long
a person who rules or commands