Limitless
Part of speech: adjective
Definition: Without limits in extent, size, quantity, and/or comprehensive perception; boundless
Example sentence: I guess what I've learned is that there are no boundaries when it comes to imagination. It's limitless.
Boundless
Part of speech: adjective
Definition: without bounds, unbounded
Example sentence: Exercising will make you look better, feel stronger, and fill you with boundless energy. Staying fit will even make you happier.