The most common and most likely answer to this crossword clue is the 6 letter word CLAGGY
C
L
A
G
G
Y
Buddy explains!
The straight part
We know that "Sticky" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sticky = claggy.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.
What does CLAGGY mean?
CLAGGY adjective- (of mud, tar, glue or the like) Sticky or tacky.
- (specifically, of a roof in a mine) Adhesive, having coal clinging to it.