There are 2 results of your search for ghosty1.
ghosty1
to push a bike along the street or footpath without a rider, letting it go to coast along by itself (as if ridden by an unseen ghost) with the aim to making it go as far as possible before it falls over: The kids in our street would compete to see who could do the best ghosty.
ghosty2
Referring to a 'bowel movement' that disappears down the S-bend before you've flushed, leaving no evidence. You know you did it, but you just can't see it!: After inspecting the contents of the toilet bowl "Hey, I just did a ghosty!"