Possible Clues:

• In torment, as I survey columnar distortion
• Shaping of a column for optical effect
• Convex curve of a column shaft
• Convex shaping of a pillar
• Cross symbol of life
• In convent, a sister hiding a little bulge?
• Classical temple feature in Staines after redevelopment
• Curvature of column, not initially curved in its current state
• Confined to convent, a sister's swelling in the middle