Nonprofessional (6)
'non-professional' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for amateur that I've seen before include "incompetent" , "inept player" , "Inept, non-professional" , "One is not professional" , "Dilettante: buff" .)
(Other definitions for layman that I've seen before include "One without professional knowledge" , "Non-ordained church member" , "Secular person" , "He is a non-professional or a non-cleric" , "Non-expert" .)