ins and outs

plural noun

1. physical characteristics, as windings and turnings, nooks, or recesses.

   the ins and outs of a subterranean passage.

2. intricacies; particulars; peculiarities.

   the ins and outs of the tax laws.

Word History and Origins

Origin of ins and outs¹

First recorded in 1880–85

Idioms and Phrases

The intricate details of a situation or process. For example, It takes a newcomer some time to learn the ins and outs of the legislative process , or David really knows the ins and outs of how this engine works . This usage alludes to the tortuous windings and turnings of a road or path. [Second half of 1600s]

Those with position and influence and those without, especially those in office versus those who are not, as in “Juan stood well both with Ins and Outs” (Byron, Don Juan , 1823). [Mid-1700s]