leaflet vs leafage

leaflet and leafage both are nouns.

Word	Noun	Adjective	Verb	Adverb
leaflet	Yes	No	No	No
leafage	Yes	No	No	No

As nouns, leafage is a hypernym of leaflet; that is, leafage is a word with a broader meaning than leaflet:

leaflet: part of a compound leaf
leafage: the main organ of photosynthesis and transpiration in higher plants

Other hypernyms of leaflet include foliage, leaf.

leaflet (noun)	leafage (noun)
a thin triangular flap of a heart valve	the main organ of photosynthesis and transpiration in higher plants
a small book usually having a paper cover
part of a compound leaf