In

In In, n.

Note: [Usually in the plural.] 1. One who is in office; -- the opposite of {out}. [1913 Webster]

2. A re["e]ntrant angle; a nook or corner. [1913 Webster]

{Ins and outs}, (a) nooks and corners; twists and turns. (b) the peculiarities or technicalities (of a subject); intricacies; details; -- used with of; as, he knew the ins and outs of the Washington power scene. [1913 Webster +PJC]

All the ins and outs of this neighborhood. --D. Jerrold. [1913 Webster]