The most common and most likely answer to this crossword clue is the 7 letter word LATHING
I've seen this crossword clue in The Times
L
A
T
H
I
N
G
Buddy explains!
The straight part
We know that "Turner's activity" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case turner's activity = lathing.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 LATHING mean?
LATHING verb- To invite; bid; ask.
- To shape with a lathe.
- To produce a three-dimensional model by rotating a set of points around a fixed axis.
- A covering of laths.