A doublet is either of two words of the same historical source, but with two different stages of entry into the language and different resultant meanings.
Examples: abbreviate/ abridge; aperture/ overture; beef/ cow; carton/cartoon; chef/ chief; cloak/ clock; coy/ quiet; crypt/ grotto; faction/ fashion; fragile/ frail; frantic/ frenetic; garden/ yard; mode/ mood; poison/ potion; praise/ prize; secure/sure; shirt/ skirt
