Intimacy is the act of becoming close to someone in a mental manner.
Intimacy is:
Intimacy is not:
Longing for a relationship selflessly is intimacy because you are not trying to know somebody for a selfish gain.
War is intimate, but it is also a pushing away. Perhaps hate is a better word. Lust is an emotion, but I've seen people mistake it for intimacy. Sex is physically intimate, but it is not an actual mingling of souls.
Ew, mental image really not needed.
Do you have a clothing fetish? Sorry, I just had to say it. Intimacy is a sense of awareness, and, carried into a personal relationship, the wish to see another succeed.