Possible Clues:

• Projection used for attaching another object
• Pipe attachment
• Rim of tart, for instance, raised
• A projecting rim or edge
• Fan with a leg all round the outside
• Projecting piece left in tooth close to canine
• Flat outer face of rolled-steel joist
• Projecting edge (on wheel, beam etc)
• It can give rail that extra edge
• Tart, say, raised from the edge