undoubtedly is a form of:

Undoubted



adjective
1.
(បច្ចេកទេស) ដែលគ្មានបញ្ហា, ឥតខ្វល់
ENGLISH MEANING
adjective
1.
Not doubted; not called in question; indubitable; indisputable; as, undoubted proof; undoubted hero.