lay‧man plural laymen [countable]
someone who is not trained in a particular subject or type of work, especially when they are being compared with someone who is [≠ expert]:
To the layman (=laymen in general) all these plants look pretty similar.
If you don't understand what the doctor says, ask to have it explained in layman's terms (=in simple language).
someone who is not a priest but is a member of a church