Non-professional
'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 "hobbyist" , "Inept, non-professional" , "I'm no expert!" , "Layperson" , "One is not professional" .)
'non-professional' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for layman that I've seen before include "He's not a cleric" , "Non-professional male" , "member of the congregation" , ""nonspecialist"" , "Non-ordained church member" .)
(Other definitions for layperson that I've seen before include "Not an expert" , "one of his flock maybe" , "Non-specialist" , "Amateur" , "parishioner?" .)