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tr.v. un·der·ran (-răn′), un·der·run, un·der·run·ning, un·der·runs
1. To run, pass, or go beneath.
2. Nautical To haul (a line or cable) onto a boat for inspection or repair.
1. Something that runs under, as:
a. An amount or a quantity produced that is less than what has been estimated.
b. The difference between this amount or quantity and what has been estimated.
2. An undercurrent.