Synonyms of duly in English:

duly


See definition of duly

adverb

1‘the document was duly signed and authorized’

SYNONYMS
properly, correctly, in due manner, rightly, fittingly, fitly, aptly, appropriately, suitably
ANTONYMS

improperly

2‘the footman duly arrived to collect Alice’

SYNONYMS
at the proper time, at the right time, in due time, on time, punctually