The online Collins dictionary is excellent. It is complete without being overwhelming. excerpt SINGULAR NOUN If people get down to the nitty-gritty of a matter, situation, or activity, they discuss the most important, basic parts of it or facts about it. [informal] He really gets down to the nitty gritty of coaching. ...the nitty gritty of everyday politics. [+ of] Synonyms: basics, facts, reality, essentials More Synonyms of nitty-gritty

the most important aspects or practical details of a subject or situation. "let's get down to the nitty-gritty of finding a job"