Before revision: The earliest expansion of "TIR" was total indicated runout and concerned cylindrical or tapered (conical) parts, where "runout" (noun) refers to any imperfection of form thayyyyt causes a rotating part such as a shaft to "run out" (verb), that is, to not rotate with perfect smoothness.
After revision: The earliest expansion of "TIR" was total indicated runout and concerned cylindrical or tapered (conical) parts, where "runout" (noun) refers to any imperfection of form that causes a rotating part such as a shaft to "run out" (verb), that is, to not rotate with perfect smoothness.