inflorescence vs catkin

inflorescence and catkin both are nouns.

Word	Noun	Adjective	Verb	Adverb
inflorescence	Yes	No	No	No
catkin	Yes	No	No	No

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

inflorescence: the flowering part of a plant or arrangement of flowers on a stalk
catkin: a cylindrical spikelike inflorescence

Other hyponyms of inflorescence include flower head, ament, umbel, corymb, flower cluster, cyme, spike.

inflorescence (noun)	catkin (noun)
the flowering part of a plant or arrangement of flowers on a stalk	a cylindrical spikelike inflorescence
the time and process of budding and unfolding of blossoms