Steamship going around pale swimmers (5)
I believe the answer is:
swans
'swimmers' is the definition.
Although both the answer and definition are plural nouns, I don't see how they can define each other.
'steamship going around pale' is the wordplay.
'steamship' becomes 'ss' (nautical abbreviation).
'going around' indicates putting letters inside.
'pale' becomes 'wan' (synonyms).
'ss' going around 'wan' is 'SWANS'.
Can you help me to learn more?
(Another definition for swans that I've seen is " Cobs and pens".)