Amateur in front of elders, cross and impertinent (8)
I believe the answer is:
inexpert
'amateur' is the definition.
(thesaurus)
'in front of elders cross and impertinent' is the wordplay.
'front of' says to take the initial letters.
'cross' becomes 'x' (**).
'and' means one lot of letters go next to another.
'impertinent' becomes 'pert' ('pert' can be a synonym of 'impertinent').
The initial letter of 'elders' is 'e'.
'in'+'e'+'x'+'pert'='INEXPERT'
(Other definitions for inexpert that I've seen before include "Amateur" , "Bumbling" , "Lacking know-how" , "Green" , "with little skill" .)