Figure in uncovered sunken ship will be adjacent to seaweed (9)
I believe the answer is:
rectangle
'figure' is the definition.
(rectangle is a kind of figure)
'uncovered sunken ship will be adjacent to seaweed' is the wordplay.
'uncovered sunken ship will' becomes 'rec' (I can't explain this - if you can you should give a lot more credence to this answer).
'be adjacent to' is a charade indicator (letters next to each other).
'seaweed' becomes 'tangle' (tangle is a type of seaweed).
'rec'+'tangle'='RECTANGLE'
'in' is the link.
Can you help me to learn more?
(Other definitions for rectangle that I've seen before include "Figure on plane" , "Quadrilateral" , "Oblong" , "regular sort of figure" , "Four-sided figure" .)