NAVE

The Nave is the central and principal part of a Christian church, extending from the entrance (the narthex) to the transepts (transverse aisle crossing the nave in front of the sanctuary in a cruciform church) or, in the absence of transepts, to the chancel (area around the altar). The nave is that part of a church set apart for the laity, as distinguished from the chancel, choir, and presbytery, which are reserved for the choir and clergy. The separation of the two areas may be effected by screens or parapets, called cancelli. The term nave derives from the Latin navis, meaning “ship,” and it has been suggested that it may have been chosen to designate the main body of the building because the ship had been adopted as a symbol of the church.

Picture taken from : http://www.pitt.edu/~medart/menuglossary/nave.htm

Acknowledgement: http://www.britannica.com/EBchecked/topic/406945/nave