tougher is a form of:

Tough



adjective
1.
(That will bend, twist; not easily cut or chewed; strong; hardy; stubborn; difficult to chew; difficult to solve) tough meat ដែលស្វិត, tough soldiers ដែលមាំមួន, tough job ដែលពិបាក, tough criminal ដែលមានចិត្ដអាក្រក់, ដែលកំណាច
Example: Tough glass Is needed for windscreens.
2.
(បច្ចេកទេស) ពិបាក, មាំ, ដែលទ្រាំទ្រភាពធ្ងន់ធ្ងរបាន, ឃោរឃៅ, ម៉ីងម៉ាត់
Example: Be / get touch (with something)
ឧទាហរណ៍៖ ប្រកាន់យកអាកប្បកិរិយាម៉ឺងម៉ាត់, ប្រកាន់យកអាកប្បកិរិយាម៉ឺងម៉ាត់, ប្រកាន់យកវិធានការមាំទាំ (ចំពោះនរណាម្នាក់)
ENGLISH MEANING
adjective
1.
Having the quality of flexibility without brittleness; yielding to force without breaking; capable of resisting great strain; as, the ligaments of animals are remarkably tough.
2.
Not easily broken; able to endure hardship; firm; strong; as, tough sinews.
3.
Not easily separated; viscous; clammy; tenacious; as, tough phlegm.
4.
Stiff; rigid; not flexible; stubborn; as, a tough bow.
5.
Severe; violent; as, a tough storm.
1.
cohesive, firm, hardy, strong, sturdy, tenacious
2.
difficult, formidable, hard, laborious, troublesome, trying
3.
callous, incorrigible, obdurate, stubborn, vicious
1.
brittle, fragile, trail
2.
easy, facile
3.
compliant, forbearing, submissive