The most common and most likely answer to this crossword clue is the 18 plus 11 letter word DECOARTEDSONTREADS ON/DECORATE
D
E
C
O
A
R
T
E
D
S
O
N
T
R
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A
D
S
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N
/
D
E
C
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A
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E
Buddy explains!
The straight part
We know that "squashes/ornament" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case squashes/ornament = decoartedsontreads on/decorate.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.