The most common and most likely answer to this crossword clue is the 10 letter word CONCERTINA
I've seen this crossword clue in Financial Times
C
O
N
C
E
R
T
I
N
A
More clues leading to the result CONCERTINA
- Fold up show in area
- Harmony in a contract
- It’s ridiculous. No! Eric can’t
- Harmony in a musical instrument
- Unison in a collapse
- Instrument of fraud sure to see American sent down?
- Crush strike gripping North? Sure thing’s short answer
- Show consisting of a musical instrument
- Instrument for deciphering Cretan icon
- A lot of interest over girl’s musical instrument
Buddy explains!

The straight part
We know that "contract" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case contract = concertina.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 CONCERTINA mean?
CONCERTINA noun- A musical instrument, like the various accordions, that is a member of the free-reed family of musical instruments, typically having buttons on both ends.
- Something resembling a concertina, such as a folded book, a bus door or a set of picture frames that are folded together.
- Coiled barbed wire for use as an obstacle.
- A type of booklet label, consisting of up to 32 pages of booklet as an insert.
- To become compressed into a shape reminiscent of a concertina
- To be drawn closer and farther apart repeatedly, or up and down, as if situated on a working concertina's folds