The most common and most likely answer to this crossword clue is the 4 plus 2 plus 8 letter word FAIR TO MIDDLING
I've seen this crossword clue in The Sunday Telegraph
F
A
I
R
T
O
M
I
D
D
L
I
N
G
More clues leading to the result FAIR TO MIDDLING
- Fixing outside broadcast, man is unexceptional
- Reasonable tune queen’s mate used in playing violin
- Admit idling for a change; that’s pretty average
- Being dishonest about imaginary cat is OK
- OK playing violin tune to mass inside
- Reasonably good string playing interrupted by song by man
- Red marigold, find it just about average
- I’d find a girl, out to save boy, modest
- Look, Tom’s admitted to cheating, OK?
Buddy explains!
The straight part
We know that "modest" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case modest = fair to middling.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.