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toughen

1 ENTRIES FOUND:
toughen /ˈtʌfən/ verb
toughens; toughened; toughening
toughen
/ˈtʌfən/
verb
toughens; toughened; toughening
Britannica Dictionary definition of TOUGHEN
: to make (something) stricter or to become stricter
[+ object]
often + up
[no object]
usually + up
: to make (someone) physically or emotionally stronger or to become physically or emotionally stronger
[+ object]
often + up
[no object]
usually + up