Detail about European plane (5)
I believe the answer is:
facet
This might be a double definition.
'detail' is the first definition.
(thesaurus)
'european plane' is the second definition.
'facet' can be an answer for 'plane' (facet plane is a kind of plane). I'm not sure about the 'european' bit.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for facet that I've seen before include "Distinct feature" , "Angle" , "Small flat surface of cut gemstone" , "Small surface (of diamond)" , "view" .)