The most common and most likely answer to this crossword clue is the 7 letter word CARINAE
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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 CARINAE mean?
CARINAE noun- A longitudinal ridge or projection like the keel of a boat.
- Part of a papilionaceous flower consisting of two petals, commonly united, which encloses the organs of fructification.
- The keel of the breastbone of birds.
- Any of several features that have a projecting central ridge