a tremble
"Her hands were trembling so badly that she could barely hold the cup of hot coffee without spilling it on her lap."
present participle of tremble
"Her hands were trembling as she held the delicate glass vase above her head."
vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze
"a quaking bog"
"the quaking child asked for more"
"quivering leaves of a poplar tree"
"with shaking knees"
"seemed shaky on her feet"
"sparkling light from the shivering crystals of the chandelier"
"trembling hands"