/nit"ee grit"ee/ , Slang.
n.
1. the essential substance or details of a matter; basics; crux: Let's skip the chitchat and get down to the nitty-gritty.
adj.
2. fundamental, detailed, or probing: nitty-gritty questions.
3. direct and practical: nitty-gritty advice; a nitty-gritty system.
[ 1960-65, Amer.; rhyming compound of uncert. orig. ]