The most common and most likely answer to this crossword clue is the 8 letter word HIPFLASK
I've seen this crossword clue in The Guardian
H
I
P
F
L
A
S
K
More clues leading to the result HIPFLASK
Buddy explains!

The straight part
We know that "this in pocket?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this in pocket? = hipflask.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 HIPFLASK mean?
HIPFLASK noun- A container designed to hold small amounts of alcohol, especially spirits, for personal consumption on the go.