Main Entry: stiff·en

Pronunciation: \ˈsti-fən\

Function: verb

Inflected Form(s): stiff·ened; stiff·en·ing \ˈsti-fə-niŋ, ˈstif-niŋ\

Date: 15th century

transitive verb : to make stiff or stifferintransitive verb : to become stiff or stiffer

— stiff·en·er \ˈsti-fə-nər, ˈstif-nər\ noun