Surveillance - survey
The noun surveillance (a good English word) comes from the French. In that language, it is the noun formed from a verb surveiller. This is not an English verb. It is pronounced quite similarly to the English verb form that has taken its place - to survey (you may want to consult AWE's article on the pronunciation of 'survey'). There is no English verb to
surveil - and in formal British English, surveillance is never a verb.