Nitty gritty

To get down to the nitty gritty means to get down to basics, the bare fundamentals, in order to resolve an issue; dates from the 1930s in America and became established in Britain and other English-speaking countries by the early 1960s. The origin is unknown despite many spurious attempts to explain it. All that can be said is that rhyming alliteration drives the expression and it may derive from grit, which is also an American word for resolve, stamina, pluck or spirit that dates from the early 19th century, or it could be associated with grit one’s teeth in showing resolve and determination. The ‘nitty’ part is the greater mystery and has prompted some sources to maintain that it was originally Afro-American slang relating to hair grooming and the removal of nits or lice, which is one way of getting down the basics one supposes.