On one's uppers is an idiom that means to be in a state of poverty or destitution. It is derived from the phrase 'up to one's uppers, ' which refers to the fact that when a person is destitute, they are often reduced to wearing only their upper garments. The two crossword solutions for this term are POOR and BUST. POOR is used to describe someone who is lacking in material possessions or money, while BUST is used to describe someone who is bankrupt or insolvent.