Longman Dictionary of Contemporary English - layman

~ n plural laymen, 1 someone who is not trained in a particular subject or type of work, especially when they are being compared with someone who is  (the layman (=laymen in general))  (technical terms not easily understood by the layman | in layman's terms (=used when explaining something in simple language))  (the GNP or, in layman's terms, the amount of goods produced by a country) 2 someone who is not a priest but is a member of a church