attrition

n. wearing down by friction, erosion; rubbing; weakening by constant harassing or abuse

Attrition may refer to:physical wearAttrition (medicine, epidemiology), the loss of participants during an experiment Attrition (dental), the loss of tooth structure by mechanical forces from opposing teethAttrition (weathering), the wearing away of rocks in the seaImperfect contrition, also known as attrition, in Catholic theologyAttrition warfare, the military strategy of wearing down the enemy by continual losses in personnel and materialCustomer attrition, a business term used to describe loss of clients or customersLanguage attrition, the loss of a first or second language or a portion of that language by either a community or an individualWar of Attrition, a limited war fought between Egypt and Israel from 1968 to 1970
See more at Wikipedia.org...

Noun
1. erosion by friction
(synonym) abrasion, corrasion, detrition
(hypernym) erosion, eroding, eating away, wearing, wearing away
2. the wearing down of rock particles by friction due to water or wind or ice
(synonym) grinding, abrasion, detrition
(hypernym) friction, rubbing
3. sorrow for sin arising from fear of damnation
(synonym) contrition, contriteness
(hypernym) sorrow, regret, rue, ruefulness
4. a wearing down to weaken or destroy; "a war of attrition"
(hypernym) decrease, lessening, drop-off
5. the act of rubbing together; wearing something down by friction
(hypernym) friction, detrition, rubbing

(n.)
The state of being worn.
  

(n.)
The act of rubbing together; friction; the act of wearing by friction, or by rubbing substances together; abrasion.
  

(n.)
Grief for sin arising only from fear of punishment or feelings of shame. See Contrition.
  

noun
wearing away, as may be caused by friction; examination showed attrition of two extensor tendons