The most common and most likely answer to this crossword clue is the 7 letter word HEAVIES
I've seen this crossword clue in The Daily Telegraph
H
E
A
V
I
E
S
More clues leading to the result HEAVIES
Buddy explains!
The straight part
We know that "thugs" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case thugs = heavies.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 HEAVIES mean?
HEAVIES noun- A villain or bad guy; the one responsible for evil or aggressive acts.
- A doorman, bouncer or bodyguard.
- A large multi-engined aircraft. (The term heavy normally follows the call-sign when used by air traffic controllers.)
- (often with "up") To make heavier.
- To sadden.
- To use power and/or wealth to exert influence on, e.g., governments or corporations; to pressure.