In the original Greek of I Peter 5:3 (an admonition to Elders):
"The entire body of Christians are also called "clergy" (xLnpoi), a peculiar people, the heritage of God." (Schaff, Vol II, P.124, History of the Christian Church).
"Neither as being Lord's over God's heritage ("kleros", the Greek word for "clergy"), but being ensamples to the flock." -I Peter 5:3
The English word "Laity" is derived from the New Testament Greek word "laos," which means "people."
The Greek word "laikos," which means "laity," is not found in the New Testament.
All in the body of Christ, whether "saints, bishops, or deacons" (Phil. l:l), are the "people" ("laos") of God (Schaff, Vol II, P.124, History of the Christian Church).
-Monk Preston
from: http://prayerfoundation.org/brief_history_of_christian_monasticism.htm