1. To shake involuntarily, as from excitement or anger; quake. See Synonyms at shake.
2. To feel fear or anxiety: I tremble at the very thought of it.
3. To vibrate or quiver: leaves trembling in the breeze.
n.
1. The act or state of trembling.
2. A convulsive fit of shaking. Often used in the plural with the.
3. trembles(used with a sing. verb)
a. An infectious viral disease of sheep that is transmitted by the tick Ixodes ricinus and affects the nervous system, causing galloping and trotting by little leaps and often prolonged trembling. Also called louping ill.
b. Poisoning of domestic animals, especially cattle and sheep, caused by eating white snakeroot or rayless goldenrod and characterized by muscular tremors and weakening. Also called milk sickness.
[Middle English tremblen, from Old French trembler, from Vulgar Latin *tremulre, from Latin tremulus, trembling; see tremulous.]
trembler n.
trembling·ly adv.
trembly adj.
tremble /trmbl/ v. [I] -bled, -bling, -bles to shake as with fear or fever, shiver: The boy trembled in fear when he saw a lion. n. a shaking motion: An earthquake hit with a jolt and a tremble.
tr
mb
l/ v. [I] -bled, -bling, -bles to shake as with fear or fever, shiver: The boy trembled in fear when he saw a lion. 
n. a shaking motion: An earthquake hit with a jolt and a tremble. 
m
b
l)
re, from Latin tremulus, trembling; see tremulous.]