The most common and most likely answer to this crossword clue is the 10 letter word INVITATION
I've seen this crossword clue in The Daily Telegraph
I
N
V
I
T
A
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More clues leading to the result INVITATION
Buddy explains!
The straight part
We know that "Request" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case request = invitation.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 INVITATION mean?
INVITATION noun- The act of inviting; solicitation; the requesting of a person's company.
- A document or verbal message conveying an invitation.
- Allurement; enticement.
- A line that is intentionally left open to encourage the opponent to attack.
- The brief exhortation introducing the confession in the Anglican communion-office.