1. Arbalestina, arbalisteria, arrow-loop, loop-hole, or similar aperture, frequently cruciform, in a medieval wall through which bowmen (arbalesters) fired arrows or bolts.
2. Store-room for arbalests (crossbows) or similar weapons.
"balistraria." A Dictionary of Architecture and Landscape Architecture. . Encyclopedia.com. (December 18, 2018). https://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/balistraria
"balistraria." A Dictionary of Architecture and Landscape Architecture. . Retrieved December 18, 2018 from Encyclopedia.com: https://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/balistraria