The most common and most likely answer to this crossword clue is the 8 letter word YEOMANRY
I've seen this crossword clue in Financial Times
Y
E
O
M
A
N
R
Y
More clues leading to the result YEOMANRY
- Any more messing and finally they will bring on the cavalry!
- Mayor with yen to relocate old group of freeholders
- Class transforming my year won without women
- Freeholders from the Old Country Railway
- A force within the TA on my year off
- Any more sad, May-made-stateless land workers?
- People farming English manor redeployed in yards?
- Farmers wanting Queen to tour Arab country in a couple of years
- The old old bloke really eviscerated militia
- Cavalry force of yore — many lost
Buddy explains!

The straight part
We know that "Class" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case class = yeomanry.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 YEOMANRY mean?
YEOMANRY noun- A class of small freeholders who cultivated their own land.
- A British volunteer cavalry force organized in 1761 for home defense and later incorporated into the Territorial Army.