When this question ("What is a 'gricer'?") was asked in Stockport Quiz League, in December 2016, the answer required was "Railway enthusiast", but the compiler had added, begrudgingly, "accept the derogatory term trainspotter if you must".
As one who was happy to be known as a trainspotter when he was growing up (there wasn't much else to do where I grew up – it was either that or play football on the rec) I had to chuckle at this; see my comment on the main Collectors page about things that some might see as a pretty pointless pastime. I suppose the point is that a trainspotter just writes down numbers, but a true enthusiast takes a broader interest – taking photographs, studying history, etc.
No one seems to know how the word 'gricer' came into being. Wikipedia mentions "speculation" that it may be derived from 'grouser' – someone who collects the birds after a shoot – but without much enthusiasm.
© Haydn Thompson 2017