This is the 743rd most frequent Romanian word.
domnului
"Domnului" means "of the gentleman" or "of the lord" in English, depending on context.
'Domnului' is the genitive form of 'domn', indicating possession (the man's).
Cartea domnului este pe masă.
The man's book is on the table.
'Domnului' is the dative form of 'domn', used to indicate the indirect object (to the man).
Am oferit un cadou domnului de la clasă.
I gave a gift to the man from the class.
'Domnului' is the genitive form of 'domn' again, showing possession (of our master).