The most common and most likely answer to this crossword clue is the 7 letter word FIANCEE
I've seen this crossword clue in The Guardian
F
I
A
N
C
E
E
More clues leading to the result FIANCEE
- In charge, one party of Africans ringed girl
- Intended fund without name ending in failure
- Intended payment to secure him a snack, regularly
- She has promised to give a hand
- I can feel endlessly excited as one anticipating match
- One taking the plunge in cafe ordered head of eel
- She is engaged in face waxing procedure essentially
Buddy explains!

The straight part
We know that "She has promised to give a hand" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case she has promised to give a hand = fiancee.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 FIANCEE mean?
FIANCEE noun- A woman who is engaged to be married.