European in biplane flying low (8)
I believe the answer is:
plebeian
'low' is the definition.
(relating to the lower classes)
'european in biplane flying' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'in' indicates putting letters inside.
'flying' indicates anagramming the letters (letters fly around into new positions).
'biplane' with letters rearranged gives 'plebian'.
'e' inserted within 'plebian' is 'PLEBEIAN'.
(Other definitions for plebeian that I've seen before include "Of the lower social classes, or uncultured" , "Lower-class; commoner" , "(Roman) commoner" , "not refined" , "Common, proletarian" .)