reduced circumstances; fallen into poverty
A literary set phrase describing a person who has come down in the world, often used in narrative or reflective contexts.
He fell into reduced circumstances and left his hometown.
Even in his fallen state, he did not lose his pride.
没落 is a common term for downfall or ruin, often used for families or businesses, whereas 落魄の身 is a literary phrase focusing on personal reduced circumstances.
落魄 (らくはく) means 'to be reduced to poverty' or 'to come down in the world', and 身 (み) means 'body' or 'oneself'. The phrase literally means 'a body that has fallen into poverty'.