The most common and most likely answer to this crossword clue is the 6 letter word ARNOLD
I've seen this crossword clue in The Daily Telegraph
A
R
N
O
L
D
More clues leading to the result ARNOLD
- Poet's outsiders from land beside river
- Right to stop an ancient poet
- Poet‘s ‘void land south of river’
- B could be Malcolm or Palmer
- A service attended by elderly poet
- At the intervals matrons ogled composer
- A service provided by aging poet
- A service provided by ancient headmaster of yesteryear
- Writer finally brought in article on historic English composer
- Ran awkwardly with aged English poet
Buddy explains!
The straight part
We know that "headmaster of yesteryear" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case headmaster of yesteryear = arnold.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.