tremble
verb
[ ˈtrɛmb(ə)l ]
• (of a person, a part of the body, or the voice) shake involuntarily, typically as a result of anxiety, excitement, or frailty.
• "Isobel was trembling with excitement"
tremble
noun
• a trembling feeling, movement, or sound.
• "there was a slight tremble in his voice"
• a physical or emotional condition marked by trembling.
Origin:
Middle English (as a verb): from Old French trembler, from medieval Latin tremulare, from Latin tremulus (see tremulous).
