related discussion: Kollegschule - College school

I don't think anything like that exists in the UK, so you're not going to find a neat direct translation. 'College school' doesn't mean anything. The closest UK equivalent is a further education college (as opposed to higher education colleges: universities) but further education is a broad term and will include apprenticeships and vocational courses as well as 16-18 year olds taking A-Levels.

https://en.wikipedia.org/wiki/Further_education

https://www.aoc.co.uk/general-further-educati...

You might also call it an adult education college,