1. At the proper time
   "she was duly apprised of the raise"
   - punctually 
2. In a due, fit, or becoming manner; as it ought to be; properly

See also: due

• Helicidae
• helicoid
• helicon
• helicopter
• helicopter view
• Helicteres
• Helicteres isora
• helio-
• Heliobacter
• Heliobacter pylori
• heliocentric
• heliocentric parallax
• heliogram
• heliograph
• heliographic
• heliogravure
• heliolatry
• heliometer
• heliopause
• heliophila
• heliopsis
• Helios
• heliosphere
• heliostat
• heliotherapy