半吞半吐　

◎ 半吞半吐 bàntūn-bàntǔ

[partly conceal and partly confess;speak with reserve (restraint);to hum and haw] 话刚说出口又缩回去

王教授把他们送到门口便站住,半吞半吐地对他们说。—— 巴金《知识阶级》