What does 'dodgy' mean in British slang?

In British slang, it depends on the context.

'The cheese is dodgy!' - Means that the cheese is out of date.

'This looks dodgy!' - Means that something looks suspicious or unsafe.

'He is a very dodgy person!' - Means that someone is suspicious and probably up to no good (ie criminal intent).

'Slough is a dodgy place!' - Means that the city of Slough is 'iffy' and should be avoided (true fact by the way).