stiffen

From Middle English stifnen, equivalent to stiff +‎ -en.

• IPA^(key): /ˈstɪfən/

• Audio (Southern England):

  (file)

• Rhymes: -ɪfən

stiffen (third-person singular simple present stiffens, present participle stiffening, simple past and past participle stiffened)

1. (transitive) To make stiff.
   • 2013 March 7, “President signs Violence Against Women Act”, in CNN‎^[1]:

     Criminal prosecutions of abusers are generally the responsibility of local authorities, but the act stiffened sentences for stalking under federal law.

   • 2016 October 11, Parija Kavilanz, “This robot makes a T-shirt from start to finish”, in CNN Business‎^[2]:

     It followed a sequence of functions: a machine cuts cloth panels to be sewn, the panels are drenched with the polymer and stiffened, a robotic arm uses suction cups to lift each panel and position it in a sewing machine. Finally, the robotic arm lifts the stitched T-shirt off the sewing machine. […] The system could work for most fabrics, with the exception of leather and waterproof materials that can't be drenched with the stiffening polymer. […] Zornow has patents pending in 10 countries for the process to stiffen fabric.

2. (intransitive) To become stiff.
   • 2003, Yoko Ogawa, The Housekeeper and the Professor:

     Bewildered by the unexpected greeting, my son stiffened, but managed a polite answer.

   • 2018 November 8, Dr. Melina Jampolis, “The real science behind fascia ailments”, in CNN‎^[3]:

     He does note that fascia, like most connective tissue in the body, stiffens with age, overuse and injury.

• starken

• stiffen up

• stiff

• infefts