walk vs boardwalk

walk and boardwalk both are nouns.

Word	Noun	Adjective	Verb	Adverb
walk	Yes	No	Yes	No
boardwalk	Yes	No	No	No

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

Other hyponyms of walk include ambulatory, catwalk, flagging, mall, promenade, pavement, sidewalk, skywalk.

walk (noun)	boardwalk (noun)
the act of traveling by foot	a walkway made of wooden boards; usually at seaside
(baseball) an advance to first base by a batter who receives four balls
a slow gait of a horse in which two feet are always on the ground
the act of walking somewhere
careers in general
a path set aside for walking
manner of walking

walk (verb)	boardwalk (verb)
obtain a base on balls
give a base on balls to
use one's feet to advance; advance by steps
accompany or escort
walk at a pace
traverse or cover by walking
take a walk; go for a walk; walk for pleasure
make walk
live or behave in a specified manner
be or act in association with