barbed wire vs barbwire

barbed wire and barbwire both are nouns.

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

As nouns, barbed wire and barbwire are synonyms defined as:

barbed wire and barbwire: strong wire with barbs at regular intervals used to prevent passage

barbed wire (noun)	barbwire (noun)
strong wire with barbs at regular intervals used to prevent passage	strong wire with barbs at regular intervals used to prevent passage