Small openings in the skin (5)
I believe the answer is:
pores
'small openings in the skin' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pores that I've seen before include "Ropes with small holes" , "Tiny holes in the skin" , "Small openings in the skin" , "Minute openings in the skin" .)