aeronautics vs avionics

aeronautics and avionics both are nouns.

Word	Noun	Adjective	Verb	Adverb
aeronautics	Yes	No	No	No
avionics	Yes	No	No	No

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

aeronautics: the theory and practice of navigation through air or space
avionics: science and technology of electronic systems and devices for aeronautics and astronautics

aeronautics (noun)	avionics (noun)
the theory and practice of navigation through air or space	science and technology of electronic systems and devices for aeronautics and astronautics