The most common and most likely answer to this crossword clue is the 8 letter word ELEVENTH
I've seen this crossword clue in The Times
E
L
E
V
E
N
T
H
More clues leading to the result ELEVENTH
- Take part in novel event held after ten
- Emerging from hotel, even though it's after ten
- The Spanish character long ago carrying priest’s ordinal?
- Out of the Top Ten for Armistice Day?
- What gets round Liberal contest's late hour?
- Organised activity hosted by wealthy regulars for a birthday
- Division line drawn in the ground
- Last minute of the hour
- Cook vehemently cutting my position as last batsman
- What about learner at race, perhaps well down the grid?
Buddy explains!

The straight part
We know that "Armistice Day" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case armistice day = eleventh.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 ELEVENTH mean?
ELEVENTH noun- The person or thing in the eleventh position.
- One of eleven equal parts of a whole.
- The note eleven scale degrees from the root of a chord.
- The ordinal form of the number eleven.