When something is limitless, there's an unending amount or supply of it. If you truly believe there are limitless possibilities in life, you see no limit to what people can achieve.
If the investor funding your business idea says she has limitless financial resources, that means the money will never run out. And if your friend promises limitless supplies of ice cream at her party, she's confident she won't run out. The ocean appears limitless — boundless in size — when you gaze at the horizon, and you may feel limitless amounts of love for the special people in your life. Limitless things have no limit, a word based in the Latin limitem, "boundary."