Definition of "transenna"

By this reversed direction of the high altars in the two churches each altar was, through the transenna, in view of the other.

1881, George Gilbert Scott, An Essay on the History of English Church Architecture

Very pertinent relationships between these grisailles of the vegetal type and Islamic transennas have been established by Eva Frodl-Kraft, between that of Obazine with palmettes enchâssées, and a transenna from the Umayyad castle of Qasr-el Heir al Gharbi (about 727-750), today reconstructed at the National Museum in Damascus, and with a plaque, probably of Syrian origin, reused over a tomb in San Marco in Venice.

1982, Meredith P. Lillich, Studies in Cistercian art and architecture, page 134

The transenne have simple geometrical designs—a common one consists of arching shapes suggestive of waves of water—and wherever these stone screens survive they give dim rippling or starlike lighting effects to church interiors.

2015, Margaret Visse, The Geometry of Love: Space, Time, Mystery, and Meaning in an Ordinary Church