legitimacy
US /ləˈdʒɪt̬.ə.mə.si/
UK /ləˈdʒɪt̬.ə.mə.si/

1.
conformity to the law or to rules
:
•
The legitimacy of the election results was questioned.
•
The court upheld the legitimacy of the new law.
2.
the ability to be defended with logic or justification
:
•
He questioned the legitimacy of her claims.
•
The scientific community debated the legitimacy of the new theory.