Steebles can mean many things, mostly in a pointless and random reply, can also be used as a replacement for swearing in frustration. It's most common use is if you are trying to confuse somebody who does not know what it means. Steebles is a great word to use in day-to-day life
What do you think you are doing punk?
Steebles mate, Steebles.
What you upto the night then?