edge vs shoulder

edge and shoulder both are nouns.

Word	Noun	Adjective	Verb	Adverb
edge	Yes	No	Yes	No
shoulder	Yes	No	Yes	No

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

edge: the outside limit of an object or area or surface; a place farthest away from the center of something
shoulder: a narrow edge of land (usually unpaved) along the side of a road

Other hyponyms of edge include border, hem, luff, border, molding, moulding, selvage, selvedge, berm, roadside, wayside.

edge (noun)	shoulder (noun)
a sharp side formed by the intersection of two surfaces of an object	a narrow edge of land (usually unpaved) along the side of a road
the outside limit of an object or area or surface; a place farthest away from the center of something	the part of a garment that covers or fits over the shoulder
a slight competitive advantage	the part of the body between the neck and the upper arm
the attribute of urgency in tone of voice	a ball-and-socket joint between the head of the humerus and a cavity of the scapula
the boundary of a surface	a cut of meat including the upper joint of the foreleg
a line determining the limits of an area

edge (verb)	shoulder (verb)
lie adjacent to another or share a boundary	push with the shoulders
provide with an edge	carry a burden, either real or metaphoric
advance slowly, as if by inches	lift onto one's shoulders
provide with a border or edge