S: (n) umbo (a slight rounded elevation where the malleus attaches to the eardrum)
S: (n) camber (a slight convexity (as of the surface of a road))
S: (n) entasis (a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight)
S: (n) tongue, knife (any long thin projection that is transient) "tongues of flame licked at the walls"; "rifles exploded quick knives of fire into the dark"
S: (n) frustum (a truncated cone or pyramid; the part that is left when a cone or pyramid is cut by a plane parallel to the base and the apical part is removed)