Is aware of swimmers getting a flying start (5)
I believe the answer is:
feels
'is aware' is the definition.
I can't judge whether this definition defines the answer.
'swimmers getting a flying start' is the wordplay.
'swimmers' becomes 'eels' (eel is a kind of aquatic vertebrate).
'getting' is a charade indicator (letters next to each other).
'start' says to take the initial letters.
The first letter of 'flying' is 'f'.
'eels' put after 'f' is 'FEELS'.
'of' is the link.
Can you help me to learn more?
(Another definition for feels that I've seen is " Is affected by".)