intimate
Very close and private, like a deep personal friendship.
Intimate describes a close, personal connection between people who trust each other deeply and share private thoughts or feelings. Your most intimate friends are the ones you can talk to about things you'd never discuss with casual acquaintances, like fears about starting middle school or worries about your family. An intimate conversation happens when two people open up honestly, sharing what really matters to them.
The word can also describe something small and cozy. An intimate gathering might be just a few close friends around a dinner table, rather than a huge party with dozens of people. An intimate restaurant has quiet corners and soft lighting where people can talk privately.
When you're intimately familiar with something, you know it deeply and thoroughly. A pianist who has practiced a piece for months is intimately familiar with every note and phrase. A detective becomes intimately familiar with the details of a case by studying every clue carefully.
Notice that intimate suggests both closeness and privacy. Intimate moments happen when people feel safe enough to be themselves completely.