Appearance, facet (6)
I believe the answer is:
aspect
I believe this is a double definition.
'appearance' is the first definition.
(aspect is a kind of appearance)
'facet' is the second definition.
(synonyms)
(Other definitions for aspect that I've seen before include "Face" , "View, outlook" , "Characteristic to be considered" , "'View, perspective (6)'" , "Look; side of building" .)