Half cooked fried fish
Throw it away, seriously. Foodborne illness risk increases with the type of food, the conditions in which it was cooked and how long it was at room temperature. Given that it was never cooked right in the first place and it probably stood out awhile you really should play it safe on this one, it's not worth getting very sick to save a bit of food, especially since it won't have good taste or texture now anyway.