areca vs Areca catechu

areca and Areca catechu both are nouns.

Word	Noun	Adjective	Verb	Adverb
areca	Yes	No	No	No
Areca catechu	Yes	No	No	No

As nouns, Areca catechu is a hyponym of areca; that is, Areca catechu is a word with a more specific, narrower meaning than areca:

areca: any of several tall tropical palms native to southeastern Asia having egg-shaped nuts
Areca catechu: southeastern Asian palm bearing betel nuts (scarlet or orange single-seeded fruit with a fibrous husk)

Other hyponyms of areca include Areca palm, betel palm.

areca (noun)	Areca catechu (noun)
any of several tall tropical palms native to southeastern Asia having egg-shaped nuts	southeastern Asian palm bearing betel nuts (scarlet or orange single-seeded fruit with a fibrous husk)