tremulous

Từ điển American Heritage Dictionary 4th

trem·u·lous (trĕmʹyə-ləs)adj.
1. Marked by trembling, quivering, or shaking.
2. Timid or fearful; timorous. [From Latin tremulus, from tremere, to tremble.] tremʹu·lous·ly adv.tremʹu·lous·ness n.