subthalamic nucleus vs karyon

subthalamic nucleus and karyon both are nouns.

Word	Noun	Adjective	Verb	Adverb
subthalamic nucleus	Yes	No	No	No
karyon	Yes	No	No	No

As nouns, karyon is a hypernym of subthalamic nucleus; that is, karyon is a word with a broader meaning than subthalamic nucleus:

subthalamic nucleus: an oval mass of grey matter located in the caudal part of the subthalamus; associated with the striate body
karyon: a part of the cell containing DNA and RNA and responsible for growth and reproduction

Other hypernyms of subthalamic nucleus include cell nucleus, nucleus.

subthalamic nucleus (noun)	karyon (noun)
an oval mass of grey matter located in the caudal part of the subthalamus; associated with the striate body	a part of the cell containing DNA and RNA and responsible for growth and reproduction