Definition of "rightfully"
adverb
comparative more rightfully, superlative most rightfully
In accordance with what is right or just; fairly.
Quotations
[T]he only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant.
1859, John Stuart Mill, “Introductory”, in On Liberty, London: John W[illiam] Parker and Son, […], page 22