inexhaustible

Etymology

From in- + exhaustible.

adj

1. Impossible to exhaust; unlimited.
   [I]t would not be very much less absurd for someone to write about New York City after having spent only a few years or a few decades in this metropolis of inexhaustible adventure, of terrifying emotional fecundity, of uncapturable character. 1946, George Johnston, Skyscrapers in the Mist, page 52