leaf vs betel leaf

leaf and betel leaf both are nouns.

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

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

leaf (noun)	betel leaf (noun)
hinged or detachable flat section (as of a table or door)	a leaf of a vine from the betel pepper
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)	betel leaf (verb)
produce leaves, of plants
turn over pages
look through a book or other written material