The most common and most likely answer to this crossword clue is the 9 letter word ASSISTANT
I've seen this crossword clue in Financial Times
A
S
S
I
S
T
A
N
T
More clues leading to the result ASSISTANT
- One leaving Francis’s place beat rear of flippant aide
- Like second coffee? Send out new aide
- Satanists abroad? Help!
- Fool is beginning to taunt soldier and aide
- Fool succeeded with heartless gibe about single aide
- One helping Turkey and half of Uzbekistan start to thrive
- Italian town? I’m lost with tense worker and aide
- Needing time for support, because sibling beat mate
- He’ll help a simpleton to sit around getting 1 No Trump
- Getting top off fruit drink, I’ll leave nasty Mark to get help
Buddy explains!

The straight part
We know that "Help" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case help = assistant.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 ASSISTANT mean?
ASSISTANT noun- Someone who is present; a bystander, a witness.
- A person who assists or helps someone else.
- Sales assistant.
- A software tool that provides assistance in some task, a wizard program.
- Having a subordinate or auxiliary position.
- Helping; lending aid or support; auxiliary.