WordNet (r) 3.0 (2006):

to the hilt
    adv 1: in full; "you are in this to the hilt" [syn: to the
           hilt, to the limit]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "to the hilt":
   ad infinitum, all over, altogether, at all points, at full length,
   completely, comprehensively, entirely, every bit, every inch,
   every whit, exhaustively, fully, globally, head and shoulders,
   heart and soul, hundred per cent, in all respects,
   in every respect, in extenso, in full, in full measure,
   inclusively, inside and out, inside out, integrally, largely,
   neck deep, on all counts, one and all, outright, overall,
   root and branch, roundly, thoroughly, through and through,
   throughout, to the brim, to the death, to the end, totally,
   tout a fait, unconditionally, unreservedly, wholly, you name it