balsa vs balsa wood

balsa and balsa wood both are nouns.

Word	Noun	Adjective	Verb	Adverb
balsa	Yes	No	No	No
balsa wood	Yes	No	No	No

As nouns, balsa and balsa wood are synonyms defined as:

balsa and balsa wood: strong lightweight wood of the balsa tree used especially for floats

balsa (noun)	balsa wood (noun)
forest tree of lowland Central America having a strong very light wood; used for making floats and rafts and in crafts	strong lightweight wood of the balsa tree used especially for floats
strong lightweight wood of the balsa tree used especially for floats