concertina vs barbed wire

concertina and barbed wire both are nouns.

Word	Noun	Adjective	Verb	Adverb
concertina	Yes	No	Yes	No
barbed wire	Yes	No	No	No

As nouns, barbed wire is a hypernym of concertina; that is, barbed wire is a word with a broader meaning than concertina:

concertina: coiled barbed wire used as an obstacle
barbed wire: strong wire with barbs at regular intervals used to prevent passage

Other hypernyms of concertina include barbwire.

concertina (noun)	barbed wire (noun)
free-reed instrument played like an accordion by pushing its ends together to force air through the reeds	strong wire with barbs at regular intervals used to prevent passage
coiled barbed wire used as an obstacle

concertina (verb)	barbed wire (verb)
collapse like a concertina