Aisle

Chambers's Encyclopaedia, Volume 1: A to Beaufort, p. 113

Aisle (from Lat. ala, 'a wing') means any lateral division of any part of a church, whether attached to the nave, choir, or transept. The number of aisles varies in different churches. In England, as a rule, there is only one on each side of the nave or choir; in most foreign countries, there are frequently two, and at Antwerp and elsewhere there are three. The continental edifices, it would seem, have antiquity in their favour for this arrangement (see BASILICA, CHURCH). The word is often incorrectly applied to the passage in a church between the pews or seats.

A black and white illustration of a church interior, specifically the aisle at Melrose Abbey. It shows a high, vaulted ceiling with pointed arches. A person is standing in the aisle, providing a sense of scale. The architecture is Gothic, with detailed stonework and a sense of depth.
Aisle—Melrose Abbey.
Source scan(s): p. 0128