The most common and most likely answer to this crossword clue is the 7 letter word KNIGHTS
I've seen this crossword clue in The Daily Telegraph
K
N
I
G
H
T
S
More clues leading to the result KNIGHTS
Buddy explains!
The straight part
We know that "pieces" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pieces = knights.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 KNIGHTS mean?
KNIGHTS noun- A young servant or follower; a trained military attendant in service of a lord.
- A minor nobleman with an honourable military rank who had served as a page and squire.
- (by extension) An armored and mounted warrior of the Middle Ages.
- (modern) A person on whom a knighthood has been conferred by a monarch.
- A brave, chivalrous and honorable man devoted to a noble cause or love interest.
- A chess piece, often in the shape of a horse's head, that is moved two squares in one direction and one at right angles to that direction in a single move, leaping over any intervening pieces.
- A playing card bearing the figure of a knight; the knave or jack.
- Any of various nymphalid butterflies of the genus Ypthima.
- (modern) A generic name for various mushrooms belonging to the fungal order gilled mushrooms; scientific name Tricholoma.
- To confer knighthood upon.
- To promote (a pawn) to a knight.