lu blue 藍色, 憂鬱, 藍調 [Card #18; 字卡第18張: 第4個單字]

Some more examples(更多例字):glue, clue, flue, flu, lu, fluid, fluent, flute, glucose, luminous, lunar, lunatic, lubricate, ludicrous, recluse, secluded, lukewarm, sluice