The most common and most likely answer to this crossword clue is the 5 plus 2 plus 6 letter word TIMON OF ATHENS
I've seen this crossword clue in The Times
T
I
M
O
N
O
F
A
T
H
E
N
S
More clues leading to the result TIMON OF ATHENS
- Wretchedly moan often: this is a fellow who certainly did
- Forget about plump female in new very big play
- Play and skip around with skinny birds only
- Footman is out and about just after that in play
- Misanthrope often portrayed in play but not rep strangely
- Men of initially high station suffer ruin in play
Buddy explains!
The straight part
We know that "a fellow who certainly did" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a fellow who certainly did = timon of athens.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.