Walk on water? (4)
I believe the answer is:
pier
'walk on water?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pier that I've seen before include "Breakwater; arch pillar" , "seaside location" , "Part of airport terminal; breakwater" , "Support for two adjacent bridge spans" , "Seaside attraction" .)