stiffen

present singular third person stiffens · participle present stiffening · participle past stiffened · past stiffened

1. transitiveTo make stiff.

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

   2013 March 7, “President signs Violence Against Women Act”, in CNN

   2 more examples

   As Willis spoke and tried to smile the voices inside him rang together like a bell, stiffening him and hollowing him and emptying him of his troubled song.

   1986, Melvin Dixon, “The Boy with Beer”, in Joseph Beam, editor, In The Life: A Black Gay Anthology, page 33

   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.

   2016 October 11, Parija Kavilanz, “This robot makes a T-shirt from start to finish”, in CNN Business, archived from the original on 19 Mar 2025

2. intransitiveTo become stiff.

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

   2003, Yoko Ogawa, The Housekeeper and the Professor

   1 more example

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

   2018 November 8, Dr. Melina Jampolis, “The real science behind fascia ailments”, in CNN