The most common and most likely answer to this crossword clue is the 3 plus 3 plus 3 plus 6 letter word PAR FOR THE COURSE
I've seen this crossword clue in The Guardian
P
A
R
F
O
R
T
H
E
C
O
U
R
S
E
More clues leading to the result PAR FOR THE COURSE
- Average salmon aimed at vulgar types we hear
- Salmon announced as part of the meal? That’s quite normal
- What's expected of orchestra, pure playing
- Fancy treacherous prof getting what one expected?
- The usual salmon to serve uncouth folk, it’s said
- Typical posture of archer, prepared
- Factor superhero represented as a normal occurrence
- Links what is to be expected there
- Average salmon caught as menu item?
- Around what typical sportsperson could expect
Buddy explains!

The straight part
We know that "Average" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case average = par for the course.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.