simple leaf vs leaf

simple leaf and leaf both are nouns.

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

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

Other hypernyms of simple leaf include foliage, leafage.

simple leaf (noun)	leaf (noun)
a leaf that is not divided into parts	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

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