Fellow going in for liberal flings in bars (5)

I believe the answer is:

reefs

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

(Other definitions for reefs that I've seen before include "Ridges of rock or sand beneath sea surface" , "Groups of submerged rock" , "coral banks" , "Submerged ridges of rock or coral near the surface of water" .)

I've seen this clue in The Hindu.

Want a hint initially instead of a full solution? Install my app