It's likely a slang term or a word specific to a particular region or community.
To figure out its meaning, I would need more context:
* Where did you hear it? Knowing the location and the people involved might help pinpoint the origin.
* What was the context? What was being said or done around the time the word was used?
Once I have more information, I might be able to help you figure out what "tooshay" means.