Steve was duplicating copies of his building contract, keeping one copy for his files and mailing the other copy to the construction company.
duplicate (DOO pli kit, DYOO pli kit) (adjective) (not comparable)
Pertaining to something that is exactly the same as something else: For some unknown reason, Louis started to receive two duplicate copies of the same magazine subscription each month.
duplicate (DOO pli kit, DYOO pli kit) (s) (noun), duplicates (pl)
Anything that is is precisely the same as something else: Elizabeth made duplicates of the medical payments before sending copies to the health insurance for refunding.
In case people lose their house keys, they should have duplicates some where in a safe and easily accessible place.