nest vs nidus

nest and nidus both are nouns.

Word	Noun	Adjective	Verb	Adverb
nest	Yes	No	Yes	No
nidus	Yes	No	No	No

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

Other hyponyms of nest include beehive, hive, bird's nest, bird nest, birdnest, drey, mouse's nest, mouse nest.

nest (noun)	nidus (noun)
a kind of gun emplacement	a nest in which spiders or insects deposit their eggs
furniture pieces made to fit close together	a central point or locus of an infection in an organism
a gang of people (criminals or spies or terrorists) assembled in one locality
a cosy or secluded retreat
a structure in which animals lay eggs or give birth to their young

nest (verb)	nidus (verb)
fit together or fit inside
gather nests
move or arrange oneself in a comfortable and cozy position
inhabit a nest, usually after building