wingspread vs wingspan

wingspread and wingspan both are nouns.

Word	Noun	Adjective	Verb	Adverb
wingspread	Yes	No	No	No
wingspan	Yes	No	No	No

As nouns, wingspread and wingspan are synonyms defined as:

wingspread and wingspan: linear distance between the extremities of an airfoil

wingspread (noun)	wingspan (noun)
distance between the tips of the wings (as of a bird or insect) when fully extended	linear distance between the extremities of an airfoil
linear distance between the extremities of an airfoil