Hanging spikes of frozen water (7)
I believe the answer is:
icicles
'hanging spikes of frozen water' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for icicles that I've seen before include "Frozen drips" , "Hanging spikes of frozen water" , "Frozen stalactites" , "Pendent spears of frozen water (7)" , "Frozen pendants" .)