happening in a way that is not regular, for example by being sometimes good and sometimes bad, or sometimes moving or changing and sometimes not

Stuttering (= sometimes good and sometimes bad) productivity figures over the last two years have made the industry unattractive to investors. 过去两年多时好时坏的产力数据使这个行业对投资者失去吸引力。

saying something, especially the first part of a word, with difficulty, for example pausing before it or repeating it several times

Jason's stuttering voice sounded louder than he liked, and he generally refrained from speaking in class. 杰森觉得自己说话结巴的声音太大，他通常忍着不在课堂上发言。

the act of saying something, especially the first part of a word, with difficulty, for example pausing or repeating a sound several times

During the 1970s and 1980s, rival theories about what causes stuttering came into vogue. 20世纪70和80年代，关于口吃原因的各种对立的理论开始流行起来。