Source : Webster's Revised Unabridged Dictionary (1913)

Interminably \In*ter"mi*na*bly\, adv.
   Without end or limit.

Source : WordNet®

interminably
     adv : all the time; seemingly without stopping; "a theological
           student with whom I argued interminably"; "her nagging
           went on endlessly" [syn: {endlessly}]