coarser is a form of:

Coarse



adjective
1.
Composed of large particles, rough or loose in texture, inferior, common, for rough work, laking in refinement, vulgar, obscene. ដែលគម្រាំង, ដែលគ្រើម, ដែលខ្ជីខ្ជារ, ដែលកម្រោល, ដែលទ្រគោះបោះបោក, ដែលជួជង, ដែលរដិបរដុប, ដែលលំបាក, ដែលនឿយ, ដែលពិបាកទ្រាំ, ដែលមិនឆ្ងាញ់ពិសារ, ដែលមិនពិរោះ, ដែលគួរឲ្យខ្លាច
Example: a coarse manner; to use coarse language, a coat of coarse cloth, a coarse thread; a man with coarse features.coarse sand ដែលមានគ្រាប់ធំៗ, coarse surface ដែលគគ្រើម, coarse manners ដែលជួជង, ដែលច្រឡោះបោះ, coarse speech ដែលគំរោះ, ដែលគ្រោតគ្រាត
ENGLISH MEANING
adjective
1.
Large in bulk, or composed of large parts or particles; of inferior quality or appearance; not fine in material or close in texture; gross; thick; rough; -- opposed to fine; as, coarse sand; coarse thread; coarse cloth; coarse bread.
2.
Not refined; rough; rude; unpolished; gross; indelicate; as, coarse manners; coarse language.