A neoplasm (disease) that involves the tonsil. The disease is tonsil neoplasm (Monarch Disease Ontology term MONDO_0021250). Also known as: neoplasm of the tonsil, neoplasm of tonsil, tonsil neoplasm (disease), tonsil tumor, tonsil tumour, tonsillar neoplasm, tonsillar neoplasms, tonsillar tumor.