neoplasm vs tumor

neoplasm and tumor both are nouns.

Word	Noun	Adjective	Verb	Adverb
neoplasm	Yes	No	No	No
tumor	Yes	No	No	No

As nouns, neoplasm and tumor are synonyms defined as:

neoplasm and tumor: an abnormal new mass of tissue that serves no purpose

Other synonyms of neoplasm include tumour.

neoplasm (noun)	tumor (noun)
an abnormal new mass of tissue that serves no purpose	an abnormal new mass of tissue that serves no purpose