What is "weak spot"

Usage examples of "weak spot".

Kurgan had failed to find his weak spot, and so had yet to get the better of him in a deal.

For thirty minutes after we'd been locked in Griffiths, Brookman and myself had searched with matches for one weak spot in either the walls or the door or that ante-chamber, a hopelessly optimistic undertaking when you consider that those walls had been built of reinforced concrete designed to withstand the sudden and violent impact of many tons of air pressure.