Limitless, a.
Having no limits; unbounded; boundless. Davies (Wit's Pilgr.).
Shades of meaning
Fernald has no entry of its own for limitless; he lists it under infinite.
Where he writes about it:
So, too, boundless, illimitable, limitless, measureless, and unlimited are loosely used in reference to what has no apparent or readily determinable limits in space or time; as, we speak of the boundless ocean. — from infinite