If you have any context about where you encountered this word, it might be easier to figure out what it was supposed to be.
For example:
* Was it in a conversation? Perhaps someone was trying to say a different word but mispronounced it.
* Was it written? Maybe there was a typo or a writing error.
* Was it in a specific context? Knowing the topic or situation might help decipher the meaning.
Please provide more information so I can help you understand what "fusishush" might be.