In a proper manner: a duly appointed official. (adverb)
At the expected time.(adverb)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "duly" in a sentence
"I know my Champs-Elysées: I have lived in the area half my life; and was in fact born about 100 metres off what the Paris Tourism office likes to call "the most beautiful avenue in the world", a tag duly picked up by the M&S advance publicity."
"Here the note-book was produced from under his pillow, and the English word duly written down."
"When Bombastês sees himself flouted, he goes mad, and hangs his boots on a tree, with this label duly displayed:"