naturalisation vs unveiling

naturalisation and unveiling both are nouns.

Word	Noun	Adjective	Verb	Adverb
naturalisation	Yes	No	No	No
unveiling	Yes	No	No	No

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

naturalisation: the introduction of animals or plants to places where they flourish but are not indigenous
unveiling: the act of beginning something new

Other hypernyms of naturalisation include debut, entry, first appearance, introduction, launching.

naturalisation (noun)	unveiling (noun)
the proceeding whereby a foreigner is granted citizenship	the act of beginning something new
changing the pronunciation of a borrowed word to agree with the borrowers' phonology	putting on display for the first time
the introduction of animals or plants to places where they flourish but are not indigenous
the quality of being brought into conformity with nature