Nickelodeon goo (5)
I believe the answer is:
slime
'nickelodeon goo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for slime that I've seen before include "Gooey seeping stuff" , "could make things sticky" , "Slippery mud; slug trail" , "Nasty slippery stuff" , "Goo" .)