To be at the coalface means to be on the front lines–working at a practical level, rather than a theoretical one. The phrase is primarily British, and derives from the image of coal miners having direct contact with exposed ore. This is part...
BOGOF n.— «The only missing name is that of Alan Shearer, who was expected to be enthused enough by Keegan’s coming to enlist in the new regime, under that scheme the supermarkets refer to as BOGOF (Buy One, Get One Free).» —“A Wise...