"Block" is the measurement of the maximum ditance an American will consider walking before deciding that the Kyoto Agreement is a bag-O'-Shite anyway and instead use their fuel hungry, energy inefficient, can-only-drive-in-straight-lines, locally built in Mexico Car instead.
It is optional in some areas to Drive around the block (in many cases this is as close as they will get to going abroad) where shooting ranges are provided by the neighbours of those areas.
Sometimes it is assumed that because of the massive influence Amercian TV has on the popular culture of entertainment-starved foreign populaces (who incidentally come from countries with insufficient knowledge or skills in harnessing the mind numbing effects of crap TV, low brow humour, political correctness at all costs, and flagrantly biased journalism) everybody knows exactly what a block is, in the same way that an engineer might know what a Mole is, or a neurosurgeon might know what Brain is. This is obviously an incorrect assumption, and has led to many miscommunications in non-american-english sepaking nations.
"I want to block planning permission for the monstrosity at the end of this road" -> leads to construction of sixteen lane motorway with flyovers making physical contact with your grandmothers chimney pots when overloaded goods lorrys carrying dried milk powder for Jamaica pass overhead
"I have a mental block" -> Teams of psychiatrists, psycholanalysts, phrenologists, quacks, ambulance chasers, experts in white coats, and gobshites with nothing better to do descent on your house to find this concentrated area of mental illness all the while waving their credentials in the air and trying to outbid each other for clientele.
"After that chilli I really need to block up my ass" -> does not bear thinking about!
Why, Ah had to walk to th' other end of the block, y'all, to buy bullets for mah rifle so that ah could shoot the damned neighbours dawg.