A joggle is a joint or projection that interlocks blocks (such as a lintel's stone blocks or an arch's voussoirs). Often joggles are semicircular and knob-shaped, so joggled stones have a jigsaw- or zigzag-like pattern.
Joggling can be found in pre-Frankish buildings, in Roman Spain and Roman France.[1] In Islamic architecture, the earliest joggles were in the desert castles of the Umayyad Caliphate, such as Qasr al-Hayr al-Sharqi.[1] In Mamluk architecture, joggling is usually combined with ablaq (alternating colors).[1] Joggling also characterize Ottoman architecture in Cairo.[2]
The protruding joggle is also called a "he-joggle", whereas the corresponding slot is called a "she-joggle".[3]