What is "hagioscope"

Hagioscope \Ha"gi*o*scope`\ (h[=a]"j[i^]*[-o]*sk[=o]p`), n. [Gr. "a`gios sacred + -scope.] An opening made in the interior walls of a cruciform church to afford a view of the altar to those in the transepts; -- called, in architecture, a squint.
--Hook.

n. (context architecture English) A small opening in an interior wall of a church, enabling those in the transept to view the high altar; sometimes called a squint

A hagioscope (from Gr. άγιος, holy, and σκοπεῖν, to see) or squint, in architecture, is an opening through the wall of a church in an oblique direction, to enable the worshippers in the transepts or other parts of the church, from which the altar was not visible, to see the elevation of the host.

Hagioscopes were also sometimes known as "leper windows" wherein a squint was made in an external wall so that lepers and other non-desirables could see the service without coming into contact with the rest of the populace.

In medieval architecture hagioscopes were often a low window in the chancel wall and were frequently protected by either a wooden shutter or iron bars. Hagioscopes are found on one or both sides of the chancel arch; in some cases a series of openings has been cut in the walls in an oblique line to enable a person standing in the porch (as in Bridgwater church, Somerset) to see the altar; in this case and in other instances such openings were sometimes provided for an attendant, who had to ring the Sanctus bell when the Host was elevated.

At St Bees Priory a purpose-built squint was included in the wall of the 14th-century chapel to give a view of the high altar. The window was low enough to allow a person to kneel whilst looking through the aperture. The hagioscope at St Mary the Virgin, Lytchett Matravers, is unusually large; although unknown in origin it provides a view to the communion table from the 16th-century north aisle. It is large enough that it is often used as a corridor for access to the chancel.

Though rarely encountered in continental Europe, they are occasionally found to serve such purposes as allowing a monk in one of the vestries to follow the service and to communicate with the bell-ringers. Sometimes squints were placed to enable nuns to observe the services without having to give up their isolation. The unusual design of the church of St Helen's in Bishopsgate, one of the largest surviving ancient churches of London, arose from its once having been two separate places of worship: a 13th-century parish church and the chapel of a Benedictine convent. On the convent side of the church a "squint" allowed the nuns to observe the parish masses; church records show that the squint in this case was not enough to satisfy the nuns, who were eventually admonished to "abstain from kissing secular persons," a habit to which it seems they had become "too prone".