Answer: soffit

AnswerCrossword Clue
SOFFITUnderside of an overhang
SOFFITArchitectural underside
SOFFITUnderside of a cornice, in architecture.
SOFFITIntrados of an arch
SOFFITOverhang's underside
soffitthe underside of an architectural structure
soffitthe underside of an architectural feature, as a beam, arch, ceiling, vault, or cornice