The best ship around? They really are funny! (7)
I believe the answer is:
screams
'they really are funny' is the definition.
The definition suggests an adverb but the answer is not.
'the best ship around?' is the wordplay.
'the best' becomes 'cream' (as in 'the cream of the crop').
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'around?' is an insertion indicator.
'cream' inserted within 'ss' is 'SCREAMS'.
Can you help me to learn more?
(Other definitions for screams that I've seen before include "Shouts" , "Shrill cries" , "Yells" .)