v. t. To run or pass under; especially (Naut.), to pass along and under, as a cable, for the purpose of taking it in, or of examining it. [ 1913 Webster ]

☞ The cable passes over the bows and stern of the boat used, while the men haul the boat along by pulling upon the cable. Totten. [ 1913 Webster ]

To underrun a hose (Naut.), to lift it up at one end, then walk along shifting one hand after another so that the water will run out. --
To underrun a tackle (Naut.), to separate its parts and put them in order. [ 1913 Webster ]