saliva vs spittle

saliva and spittle both are nouns.

Word	Noun	Adjective	Verb	Adverb
saliva	Yes	No	No	No
spittle	Yes	No	No	No

As nouns, saliva and spittle are synonyms defined as:

saliva and spittle: a clear liquid secreted into the mouth by the salivary glands and mucous glands of the mouth; moistens the mouth and starts the digestion of starches

Other synonyms of saliva include spit.

saliva (noun)	spittle (noun)
a clear liquid secreted into the mouth by the salivary glands and mucous glands of the mouth; moistens the mouth and starts the digestion of starches	a clear liquid secreted into the mouth by the salivary glands and mucous glands of the mouth; moistens the mouth and starts the digestion of starches