flyleaf vs leaf

flyleaf and leaf both are nouns.

Word	Noun	Adjective	Verb	Adverb
flyleaf	Yes	No	No	No
leaf	Yes	No	Yes	No

As nouns, leaf is a hypernym of flyleaf; that is, leaf is a word with a broader meaning than flyleaf:

flyleaf: a blank leaf in the front or back of a book
leaf: a sheet of any written or printed material (especially in a manuscript or book)

Other hypernyms of flyleaf include folio.

flyleaf (noun)	leaf (noun)
a blank leaf in the front or back of a book	hinged or detachable flat section (as of a table or door)
	a sheet of any written or printed material (especially in a manuscript or book)
	the main organ of photosynthesis and transpiration in higher plants

flyleaf (verb)	leaf (verb)
	produce leaves, of plants
	turn over pages
	look through a book or other written material