What it means
Homie is your close friend, your people, the one who's solid with you and around for the small stuff and the messy stuff too. It's warm, casual, and usually said with real affection.
Usage examples
"My homie has my back no matter what."
"Thanks for the ride, homie."
"That's my homie, we've been locked in since middle school."
"You good, homie? Hit me if you need anything."
Where it comes from
Homie comes from homeboy in African American English, originally for someone from your neighborhood or home turf. Over time it softened into homie and spread wider in US slang, keeping that same feel of closeness, trust, and shared roots even when it's just about a tight friend.