The Collaborative International Dictionary of English v.0.48:
desensitisation \desensitisation\ n. same as desensitization. Syn: desensitization. [WordNet 1.5]WordNet (r) 3.0 (2006):
desensitisation n 1: the process of reducing sensitivity; "the patient was desensitized to the allergen" [syn: desensitization, desensitisation]