On one’s beam-end/ends

To be on one’s beam-end or beam-ends is to be destitute or almost destitute and dates in this figurative sense from the 1830s. The origin is almost certainly nautical and is first recorded in this literal sense from at least the late 18th century. The beams referred to are the crossbeams of a ship that run transversely across the entire length of a ship. If a ship was on these beam-ends, it would be very close to floundering, hence the origin and figurative use of the expression.