boffin

noun [Br.] [colloq]
1. (m/ f) científic
2. (m / f) estudiós

The definition given in dictionaries for 'boffin' is: "a scientist, especially one doing research" However, I also know it as being fairly synonymous with 'swot' or 'brainy person'. I wasn't sure why I couldn't find this definition in any dictionary, then I found an article on the Internet which discusses the word 'boffin' and says:

"[...] I'd argue that — in Britain at least — boffin has never quite taken on the highly negative associations that Professor Fell ascribes to it [...] but for many young people in Britain, it is indeed derogatory, for a different reason. When it came into fashion among them some 20 years ago, it took on much the same sense that my generation gave to swot, as a disparaging description of someone good at school work — a person acknowledged to be brainy, but inoffensive and definitely not respected[...]"

The whole article can be found here:
http://www.worldwidewords.org/topicalwords/tw-bof1.htm