Cruciform is a term for physical manifestations resembling a common cross or Christian cross. The label can be extended to architectural shapes, biology, art, and design.
Peterborough Cathedral
Librarian Humfrey Wanley holding a facsimile copy of a cruciform Greek manuscript (Lectionary 150)
Jetstream 31 with cruciform tail
A cross-in-square or crossed-dome plan was the dominant architectural form of middle- and late-period Byzantine churches. It featured a square centre with an internal structure shaped like a cross, topped by a dome.
Panagia Chalkeon, an 11th-century cross-in-square church in Thessaloniki. View from the north east.
Plan of a typical cross-in-square church; based on the 10th-century Myrelaion in Constantinople.
Plan of the Chora Church in Constantinople
Compact cross-in-square plan, based on the Cattolica in Stilo. The naos is the central liturgical area and bema the sanctuary.