The most common and most likely answer to this crossword clue is the 5 letter word SHAFT
I've seen this crossword clue in Financial Times
S
H
A
F
T
More clues leading to the result SHAFT
Buddy explains!

The straight part
We know that "part of golf club" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of golf club = shaft.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 SHAFT mean?
SHAFT noun- The entire body of a long weapon, such as an arrow.
- The long, narrow, central body of a spear, arrow, or javelin.
- (by extension) Anything cast or thrown as a spear or javelin.
- Any long thin object, such as the handle of a tool, one of the poles between which an animal is harnessed to a vehicle, the driveshaft of a motorized vehicle with rear-wheel drive, an axle, etc.
- A beam or ray of light.
- The main axis of a feather.
- The long narrow body of a lacrosse stick.
- A vertical or inclined passage sunk into the earth as part of a mine
- A vertical passage housing a lift or elevator; a liftshaft.
- A ventilation or heating conduit; an air duct.
- Any column or pillar, particularly the body of a column between its capital and pedestal.
- The main cylindrical part of the penis.
- The chamber of a blast furnace.
- To fuck over; to cause harm to, especially through deceit or treachery.
- To equip with a shaft.
- To fuck; to have sexual intercourse with.