Other forms: homelessly
If you're homeless, you don't have any place to live — you might be without a roof over your head, or even without a country to call your own. Refugees living in temporary camps because of civil war are homeless.
Homeless refugees aren't really citizens of any land, while other homeless people are in a more temporary bad spot, having lost their homes because of financial trouble, illness, or other bad luck. Sometimes the word homeless is used as a noun for a person in such a predicament, but it's more correct and thoughtful to use the word as an adjective — that way, a homeless person isn't solely defined by not having a home.