The most common and most likely answer to this crossword clue is the 7 letter word ABYSSAL
I've seen this crossword clue in Independent
A
B
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A
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More clues leading to the result ABYSSAL
- Sailor, Yankee with girl climbing on the bed?
- Very deep article has girl reflecting on past
- A little baby’s sallow from a very deep bed
- Initially dislodged, small girl back on bed below?
- Times supporting article girl sent up regarding ocean trenches?
- A handy girl to call up – but lacking ‘bottom’?
- From the deep area near a lake entered by ship
Buddy explains!

The straight part
We know that "regarding ocean trenches?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case regarding ocean trenches? = abyssal.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 ABYSSAL mean?
ABYSSAL adjective- Belonging to, or resembling, an abyss; unfathomable.
- Of or belonging to the ocean depths, especially below 2000 metres (6500 ft): abyssal zone.
- Pertaining to or occurring at excessive depths in the earth's crust; plutonic.