What term refers to something worn out or ruined because of age or neglect?

The term that refers to something worn out or ruined because of age or neglect is "decrepit." This word specifically conveys a sense of deterioration and decline due to the effects of time and lack of maintenance. It often describes buildings, objects, or materials that have become weakened and worn over time, emphasizing the severity of their condition.

In contrast, "newfangled" describes something that is new and innovative, often with a connotation of being overly trendy or modern; it does not relate to age or deterioration. "Aged" simply indicates that something is old but does not inherently imply that it is in a ruinous or neglected state. "Fragile," on the other hand, denotes delicacy and susceptibility to breakage, but does not specifically refer to the effects of age or neglect. Therefore, "decrepit" is the most fitting term for conveying the idea of something that has been worn out or ruined over time.