stiffen

/ˈstɪfən/

/ˈstɪfɪn/

Other forms: stiffened; stiffening; stiffens

To stiffen is to become stiff or unbending. If your legs stiffen during a long plane flight, you'll want to stretch them out once you land.

You can stiffen something deliberately, like when you stiffen a package with cardboard to protect it in the mail. You can also stiffen in reaction to something: "The spooky creaking sounds upstairs made us stiffen in terror." The earliest sense of this verb was "make steadfast," from a now-obsolete meaning of stiff, "gain strength."

Definitions of stiffen

1. verb

   make stiff or stiffer
   “Stiffen the cream by adding gelatine”

   antonyms:

   loosen

   make loose or looser

   types:

   starch

   stiffen with starch

   buckram

   stiffen with or as with buckram

   ossify, petrify, rigidify

   make rigid and set into a conventional pattern

   type of:

   alter, change, modify

   cause to change; make different; cause a transformation
2. verb

   become stiff or stiffer
   “He stiffened when he saw his boss enter the room”

   antonyms:

   loosen

   become loose or looser or less tight

   types:

   rigidify

   become rigid

   type of:

   change

   undergo a change; become different in essence; losing one's or its original nature
3. verb

   restrict
   “stiffen the regulations”

   synonyms: constrain, tighten, tighten up

   type of:

   bound, confine, limit, restrain, restrict, throttle, trammel

   place limits on (extent or access)