昙 曇 tan2
dark clouds

strokes 16
radical
日
日
strokes after radical 12
瞿昙 瞿曇 qu2 tan2
Gautama, surname of the Siddhartha, the historical Buddha

昙花 曇花 tan2 hua1
Dutchman's Pipe (Epiphyllum oxypetalum)

昙花一现 曇花一現 tan2 hua1 yi1 xian4
lit. the night blooming cactus shows once; flash in the pan (idiom); short-lived