Other forms: toughened, toughening, toughens
To toughen is to make stronger or more able to endure. Toughen the glass, toughen up, toughened by the work.
Toughened glass is heat-treated so that it breaks into blunt pieces instead of shards, which is why car side windows and shower screens use it. Of a person it means becoming more resilient, and toughen up is usually said unkindly. Note the -en ending, which makes verbs of adjectives as in harden.
1verbtoughenTo make stronger or more able to endure.
“The army training toughened him up, both physically and mentally.”
toughen is a strengthening.
Proto-Indo-European
*denḱ- — to bite
Proto-Germanic
*tanhuz — fitting; clinging; tenacious; tough
Proto-West Germanic
*tą̄h(ī)
Old English
tōh — tough, tenacious, holding fast together; pliant; sticky, glutinous, clammy
Middle English
tough
English
tough
English, today
toughen
Built from
From tough + -en. tough comes from Middle English tough, towgh, tou, toȝ, from Old English tōh (“tough, tenacious, holding fast together; pliant; sticky, glutinous, clammy”), from Proto-West Germanic tą̄h(ī), from Proto-Germanic tanhuz (“fitting; clinging; tenacious; tough”), from tinganą (“to press upon, throng”), from Proto-Indo-European denḱ- (“to bite”). 2 Cognate with stq toai (“tough”), bar zaach, zach (“tough”), Dutch taai (“tough”), German zäh, zähe (“tough”), li tiee (“tough”), lb zéi (“tough”); also Ancient Greek δάκνω (“to bite”), Albanian danë, darë (“tongs; pincers; pliers”), Sanskrit दशति (“to bite”).
Etymology from Wiktionary, CC BY-SA