如果非要译,我觉得只能这样大伯:the paternal oldest uncle (who is)older than the father(括号里的可省略,下同)二叔:the paternal second oldest uncle (who is)younger than the father三伯: the paternal third oldest uncle (who is)older than the father老舅:the maternal oldest uncle (who is)older than the mother老大:the oldest brother老二:the second oldest brother