Flower engulfed by receding shoreline (4)
I believe the answer is:
nile
'flower' is the definition.
(Nile River is an example)
'engulfed by receding shoreline' is the wordplay.
'receding' shows that the letters should be reversed in order.
'engulfed by' indicates the answer is hidden within the clue.
'elin' is hidden in the letters of 'shoreline'.
'elin' back-to-front is 'NILE'.
(Other definitions for nile that I've seen before include "River at Luxor" , "'The longest river, blue and white (4)'" , "White or Blue river of Africa" , "long-distance runner in Africa" , "Cleopatra's river" .)