leaf vs simple leaf

leaf and simple leaf both are nouns.

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

As nouns, simple leaf is a hyponym of leaf; that is, simple leaf is a word with a more specific, narrower meaning than leaf:

leaf (noun)	simple leaf (noun)
hinged or detachable flat section (as of a table or door)	a leaf that is not divided into parts
a sheet of any written or printed material (especially in a manuscript or book)
the main organ of photosynthesis and transpiration in higher plants

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