1.continuing forever without end;
there are infinitely many possibilities
2.with unflagging resolve;
dance inspires him ceaselessly to strive higher and higher toward the shining pinnacle of perfection that is the goal of every artiste
3.(spatial sense) seeming to have no bounds;
the Nubian desert seemed to stretch out before them endlessly
4.all the time; seemingly without stopping;
a theological student with whom I argued interminably