undertone vs meaning

undertone and meaning both are nouns.

Word	Noun	Adjective	Verb	Adverb
undertone	Yes	No	No	No
meaning	Yes	Yes	No	No

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

undertone: a subdued emotional quality underlying an utterance; implicit meaning
meaning: the idea that is intended

Other hypernyms of undertone include substance.

undertone (noun)	meaning (noun)
a pale or subdued color	the idea that is intended
a subdued emotional quality underlying an utterance; implicit meaning	the message that is intended or expressed or signified
a quiet or hushed tone of voice

undertone (adjective)	meaning (adjective)
	rich in significance or implication