fishing license vs fishing permit

fishing license and fishing permit both are nouns.

Word	Noun	Adjective	Verb	Adverb
fishing license	Yes	No	No	No
fishing permit	Yes	No	No	No

As nouns, fishing license and fishing permit are synonyms defined as:

fishing license and fishing permit: a license authorizing the bearer to fish during a specified period of time

Other synonyms of fishing license include fishing licence.

fishing license (noun)	fishing permit (noun)
a license authorizing the bearer to fish during a specified period of time	a license authorizing the bearer to fish during a specified period of time