a fault that is greater in yourself than in the person you are finding fault with
This phrase comes from Matthew 7 : 3 : Why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thy own eye?
broad in the beam
fat round the hips – informal
A beam was one of the horizontal transverse timbers in a wooden ship and so the word came to refer to a ship's breadth at its widest point. It is from this sense that the current meaning of broad in the beam developed.
off beam = way off beam
on the wrong track
mistaken - informal
Originally, this phrase referred to the radio beam or signal used to guide aircraft.
1997 - Anthony Barnett - This Time I sample the press coverage to illustrate how large sections of the Fourth Estate were way off beam in their conviction that voters want the country steered back towards Great Englishness.
on your beam ends
near the end of your resources
The beam referred to here is one of the main horizontal transverse timbers of a wooden ship. The phrase originated as the nautical term on her beam ends and was used of a ship that had heeled over on its side and was almost capsizing.