dig: [13] The origins of dig are not altogether clear. It does not appear to have existed in Old English, although it has been speculated that there was an Old English verb *dīcigian, never recorded, derived from dīc ‘ditch’ (the standard Old English verbs for ‘dig’ were delfan and grafan, whence modern English delve and grave). Another theory is that it was borrowed from Old French diguer ‘make a dyke, hollow out the earth’. This was a derivative of the noun digue ‘dyke’, which itself was borrowed from a Germanic source that also produced Old English dīc (and indeed modern English dyke). => ditch, dyke
