The most common and most likely answer to this crossword clue is the 8 plus 7 letter word SLEEPING PARTNER
I've seen this crossword clue in The Guardian
S
L
E
E
P
I
N
G
P
A
R
T
N
E
R
More clues leading to the result SLEEPING PARTNER
- One makes money out of it?
- Foolishly presenting pearl to investor
- Idle business associate one often has relations with?
- Investor who only backs naps?
- One in business who has retired?
- Retired investor?
- Investor representing pal in a bad way
- Pregnant rep lies about investor
- Silent shareholder out East for example
Buddy explains!
The straight part
We know that "Idle business associate/one often has relations with" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case idle business associate/one often has relations with = sleeping partner.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.