It is the part that holds the wall over an opening (door or window), and thus prevents the weight of the building from falling upon you.
If you see a strong and well established lintel, you feel safe from the environment.
If the lintel presents danger of breaking it may mean you are afraid of problems you cannot solve on your own and that are caused by external factors.
[1]A sign of a change of residence to a larger home.
[2](See Also: Doorstep)
[3]