"Ghostbusters" goo (5)
I believe the answer is:
slime
'ghostbusters goo' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for slime that I've seen before include "Nasty slippery stuff" , "Gooey seeping stuff" , "Slippery mud; slug trail" , "Gunk" , "Goo" .)