Clear ship at sea will get round (9)
I believe the answer is:
spherical
'round' is the definition.
(similar in meaning)
'clear ship at sea' is the wordplay.
'at sea' is an anagram indicator.
'clear'+'ship'='clearship'
'clearship' anagrammed gives 'SPHERICAL'.
'will get' is the link.
(Other definitions for spherical that I've seen before include "Like a ball" , "Like cannonballs" , "Ball shaped" , "Globe-shaped" , "As balls" .)