Open English Wordnet
Adverbs
(r)endlessly, ceaselessly, incessantly, unceasingly, unendingly, continuouslywith unflagging resolve“dance inspires him ceaselessly to strive higher and higher toward the shining pinnacle of perfection that is the goal of every artiste”
(r)interminably, endlesslyall the time; seemingly without stopping“a theological student with whom I argued interminably”, “her nagging went on endlessly”