false vs off-key

false and off-key both are adjectives.

Word	Noun	Adjective	Verb	Adverb
false	No	Yes	No	Yes
off-key	No	Yes	No	No

As adjectives, false and off-key are synonyms defined as:

Other synonyms of false include sour.

false (adjective)	off-key (adjective)
not in accordance with the fact or reality or actuality	inaccurate in pitch
not genuine or real; being an imitation of the genuine article
adopted in order to deceive
designed to deceive
(used especially of persons) not dependable in devotion or affection; unfaithful
arising from error
inaccurate in pitch
deliberately deceptive
erroneous and usually accidental
inappropriate to reality or facts

false (adverb)	off-key (adverb)
in a disloyal and faithless manner