(ˈ)krȯ|set noun
( -s )
Etymology: French crossette, diminutive of crosse crosier (pastoral staff) — more at crosier
1. : a projection at a corner of the architrave of a door or window — called also ancon, ear, elbow
2. : a projection in a voussoir (as of a flat arch) fitting into a corresponding recess in the adjacent voussoir