金剛般若波羅蜜經註解 1.115

1.115

梵語斯陀含，華言一來，此聲聞第二果也。蓋欲界有九品思惑，前六品已斷，後三品未斷，更須欲界一度受生，故云一來。

In Sanskrit 'sakṛdāgāmin', in Chinese 'once-returner'. This is the second fruition of a śrāvaka. In the desire realm there are nine grades of delusions of thought; the first six grades have been severed, and the latter three grades are not yet severed, so one must undergo birth once more in the desire realm; hence it is called 'once-returner'.