Sea foam close to outcrop, birds circling around (5)
I believe the answer is:
spume
'sea foam' is the definition.
(I've seen this before)
'close to outcrop birds circling around' is the wordplay.
'close to' says to take the final letters (the close of something is the end).
'birds' becomes 'emus' (emu is a kind of bird).
'circling' means one lot of letters goes inside another (circling can mean going around or containing).
'around' shows that the letters should be reversed in order.
The final letter of 'outcrop' is 'p'.
'p' going inside 'emus' is 'emups'.
'emups' reversed gives 'SPUME'.
(Other definitions for spume that I've seen before include "Sea foam, froth" , "Foam on waves" , "Froth on waves" , "Surf" .)