If something is 'up for grabs', it is available.
Is this last biscuit up for grabs? I'm starving.
There are some great prizes up for grabs in tonight's pub quiz.
There are three scholarships up for grabs. I'm definitely going to apply.
Don't confuse it with
The expression 'up for grabs' is always plural, even when we're talking about a single thing.
Incorrect: There is still one prize up for grab.
Correct: There is still one prize up for grabs.
The photo above won the 'animal behaviour' category in the 2012 British Wildlife Photography competition. Amanda Hayes took this picture in Northumberland, in north east England. The photographer spent a week trying to photograph gulls stealing the sand eels from puffins. Luckily for the puffin, it managed to free itself from the gull's grasp.