A lot vs. Alot: 9 Grammatical Pitfalls
1956, U.S. Air Force back-formation from attrition which attained currency during the Vietnam War. (A 17c. attempt at a verb produced attrite). Related: Attrited; attriting.
An expected rate of loss or attrition: Attrit can refer to an expected rate of loss or attrition (Air Force)