The most common and most likely answer to this crossword clue is the 9 letter word ANALOGOUS
I've seen this crossword clue in The Daily Telegraph
A
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A
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O
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More clues leading to the result ANALOGOUS
- A paper turns up containing a device that's similar
- Strangely, no US gaol area is comparable
- Advanced paper turns up containing a device that’s similar
- Similar opening about a trademark
- An American incorporating a company emblem which is similar
- A record, in a sense, must be equivalent
- Like a record, in a sense
- A sense to hold a list that is similar
- Similar to device in sauna set-up
Buddy explains!

The straight part
We know that "equivalent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case equivalent = analogous.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 ANALOGOUS mean?
ANALOGOUS adjective- Having analogy; corresponding to something else; bearing some resemblance or proportion (often followed by "to".)
- Functionally similar, but arising through convergent evolution rather than being homologous.