The most common and most likely answer to this crossword clue is the 6 letter word ENGELS
E
N
G
E
L
S
More clues leading to the result ENGELS
- Becomes hard to follow case of European political theorist
- Nurses must protect limb that’s turned red
- Bearded lefty is regularly snug in slippers
- Becomes hard to follow case of Etonian political theorist
- 16’s collaborator points to broken legs
- Marx brother or English golfer
- English financiers beheaded communist
- Marx brother, English golfer
- Socialist theatre backers making a turn irate ultimately
- Communist sticks by workers, wiping brow
Buddy explains!

The straight part
We know that "Name among European set, foremost of socialists" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case name among european set, foremost of socialists = engels.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.