1. Erosion by friction
   - abrasion, attrition, corrasion 
2. The wearing down of rock particles by friction due to water or wind or ice
   - grinding, abrasion, attrition 
3. Effort expended in moving one object over another with pressure
   - friction, rubbing

Derived forms: detritions

Type of: eating away, effort, elbow grease, eroding, erosion, exertion, friction, rubbing, sweat, travail, wearing, wearing away

• ungulate
• ungulated
• ungummed
• ungusseted
• unhallow
• unhallowed
• unhampered
• unhand
• unhandy
• unhappily
• unhappiness
• unhappy
• unharassed
• unhardened
• unharmed
• unharmonious
• entomologic
• entomological
• entomologist
• entomology
• entomophilous
• entomophobia
• Entomophthora
• Entomophthoraceae
• Entomophthorales