The term 'become physically weaker' can be summarized by three crossword solutions: FRAIL (5 letters), Eroding (7 letters), and PREY (4 letters). FRAIL is an adjective meaning 'physically weak or delicate, ' often used to describe elderly people. Eroding is a verb meaning 'gradually destroy or be gradually destroyed, ' often used to describe the effects of weathering on physical objects. PREY is a noun meaning 'an animal hunted for food, ' suggesting that the subject of the term is being hunted or attacked. Together, these three words suggest that the subject of the term is becoming physically weaker due to external forces.