阿斗

1. • A-dou, nickname of Liu Shan 刘禅 liúshàn (207-271), son of Liu Bei, reigned as Shu Han emperor 233-263
2. • weak and inept person

     fig.

Character by character

• 阿(ā)prefix used before monosyllabic names, kinship terms etc to indicate familiarity
• 斗(dǒu)dry measure for grain equal to ten 升 shēng or one-tenth of a 石 dàn