The most common and most likely answer to this crossword clue is the 8 letter word BLU-TACK
I've seen this crossword clue in Independent
B
L
U
-
T
A
C
K
More clues leading to the result BLU-TACK
Buddy explains!
The straight part
We know that "sticky stuff" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sticky stuff = blu-tack.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.