trembling vs shivering

trembling and shivering both are nouns.

Word	Noun	Adjective	Verb	Adverb
trembling	Yes	Yes	No	No
shivering	Yes	Yes	No	No

As adjectives, trembling and shivering are synonyms defined as:

trembling and shivering: vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze

Other synonyms of trembling include shaky.

trembling (noun)	shivering (noun)
a shaky motion	a sensation of cold that often marks the start of an infection and the development of a fever

trembling (adjective)	shivering (adjective)
vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze	vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze