Attrition (dental)
WordNet
noun
(1) The act of rubbing together; wearing something down by friction
(2) A wearing down to weaken or destroy
"A war of attrition"
(3) Sorrow for sin arising from fear of damnation
(4) The wearing down of rock particles by friction due to water or wind or ice
(5) Erosion by friction
WiktionaryText
Etymology
From , from the verb , past participle of , from + .
Noun
- wearing or grinding down by friction
- A gradual, natural reduction in membership or personnel, as through retirement, resignation, or death
- The loss of participants during an experiment