Duly is an adverb which means in line with what is appropriate, following proprieties, as may be expected. Duly has evolved from the fourteenth century duweliche, meaning rightly, properly. Duly means in a due manner, according to Google’s Ngram, use of the word duly peaked in the mid-1600s and has dropped ever since.
Dully is an adverb which means in a lackluster manner, without excitement, lacking spirit or verve. Dully is an adverb form of dull, an adjective first used in 1200 to mean stupid, then in the early thirteenth century to mean blunt, not sharp. Dull comes from the Old English word dol meaning slow-witted, stupid.
If the plaintiff was duly elected or appointed, he is an insured under the policy and the exclusion would be triggered. (The National Law Review)
With his company’s 10-year anniversary to celebrate, the stakes were duly raised, and he met the challenge with a late-night bacchanal, one so good he managed to lose his wallet during it. (The New York Times)
When dealing with the homeless issue, PCSO Lt. Troy Sander makes sure all parties involved are duly respected. (The Auburn Journal)
But, be honest, it’s the Donner Party and the C-word (not sensationally featured in museum displays and literature but duly noted in the aptly titled “Desperation” display) that drew the healthy crowd of tourists I encountered roaming the halls one recent afternoon. (The La Crosse Tribune)
Less worried about the drama than about the people who comprise it, California records conversations in their entirety, sometimes a little dully, but always with the air of truth, the script aware that large changes can arise from the smallest details of a conversation. (The Hollywood Reporter)
It seems that the band have become too used to the album, and now it has become dully robotic. (The Edinburgh Reporter)
Hopefully the dully familiar elements will slide away as the series progresses, revealing the hard-core of the crime, which remains bloody and compelling, at Winter’s heart. (The New Zealand Herald)