Definition of stiffening in English:

stiffening

noun

  • [mass noun] Material used to stiffen a garment, fabric, or other object.

    • ‘When required, he will apply stiffening and restore the color of the seams.’
    • ‘We usually only find it necessary or helpful to apply stiffening for brief periods, typically for no more than 5% of insertion time.’

Pronunciation:

stiffening

/ˈstɪfnɪŋ/