Hole, opening (8)
I believe the answer is:
aperture
I believe this is a double definition.
'hole' is the first definition.
(I know that aperture is a type of hole)
'opening' is the second definition.
(I know that aperture is a type of opening)
(Other definitions for aperture that I've seen before include "Opening, to let light enter a camera perhaps" , "Crack" , "Opening (for a photographer?)" , "Eye" , "Opening, gap" .)