The most common and most likely answer to this crossword clue is the 6 letter word HINDER
I've seen this crossword clue in The Guardian
H
I
N
D
E
R
More clues leading to the result HINDER
- Impede farm-worker about to retire
- . Hot slice from Domino’s put in woman’s hamper
- Obstruct growth in deregulated housing
- Hamper‘s back — starts to eat ravenously
- That woman hiding Independent in hamper
- Stop back
- Laugh in derision comprehending stunt
- Obstruct from behind, erroneously
- Rear royal figure to stop progress
- Henry in revolutionary communist bar
Buddy explains!

The straight part
We know that "Hamper" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hamper = hinder.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 HINDER mean?
HINDER verb- To make difficult to accomplish; to act as an obstacle; to frustrate.
- To delay or impede; to keep back, to prevent.
- To cause harm.
- Located at the rear (most often said of animals' body parts).
- The buttocks.
- Of or belonging to that part or end which is in the rear or hind, or which follows.