verbalisation vs diction

verbalisation and diction both are nouns.

Word	Noun	Adjective	Verb	Adverb
verbalisation	Yes	No	No	No
diction	Yes	No	No	No

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

Other hypernyms of verbalisation include choice of words, phraseology, phrasing, verbiage, wording.

verbalisation (noun)	diction (noun)
the activity of expressing something in words	the manner in which something is expressed in words
the words that are spoken in the activity of verbalization	the articulation of speech regarded from the point of view of its intelligibility to the audience