The most common and most likely answer to this crossword clue is the 9 letter word UMPTEENTH
U
M
P
T
E
E
N
T
H
More clues leading to the result UMPTEENTH
- Furiously thump boxing youngster, the latest of many
- Put the men to work well down the order
- Put the men into another formation — the last of many?
- Hesitating private then breaks free – the last of many
- The last of many put the men in a spin
- Adolescent a little tempted to get into speed after university — the latest of many
- Match official with clout taking number — the latest in a long line
- The men put away the last of many
- Mash, then--um--pet, the last in a long line
Buddy explains!

The straight part
We know that "the latest in a long line" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the latest in a long line = umpteenth.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.
What does UMPTEENTH mean?
UMPTEENTH adjective- (often slightly derogatory) Occurring in a relatively large but unspecified position in a sequence.