I'm not sure why the Brits call a fully featured 'integrated amplifier' an 'Amplifier'. I'm sure it's just another example of the many idiosyncrasies of the English language and its enigmatic [eccentric] users. We've all got our favourites. Mine, a car 'hood'. In England it's called a 'bonnet'. Cute. What's the phrase? 'Two nations divided by a common language.'