audio vs frequency

audio and frequency both are nouns.

Word	Noun	Adjective	Verb	Adverb
audio	Yes	No	No	No
frequency	Yes	No	No	No

As nouns, frequency is a hypernym of audio; that is, frequency is a word with a broader meaning than audio:

Other hypernyms of audio include frequence, oftenness.

audio (noun)	frequency (noun)
the sound elements of television	the number of observations in a given statistical category
a recording of acoustic signals	the ratio of the number of observations in a statistical category to the total number of observations
an audible acoustic wave frequency	the number of occurrences within a given time period
the audible part of a transmitted signal