• 欠陥けっかん — defect; flaw
• 陥没かんぼつ — cave-in; depression
• 陥落かんらく — fall; collapse (city, position)
• 陥おちいる — to fall into; to get trapped in a bad situation
• 陥おとしいれる — to entrap; to trick; to frame

The left side shows a hill or slope (こざとへん), and the right side comes from a phonetic element meaning “to fall” or “to sink.” Together they form the idea of slipping down, being trapped, or falling into a difficult spot.