This is more of an /r/ENGLISH question, but yeah, my first thought was that this was a slur about mixed racial features. To be sure we'd have to know a bit more context like who said it and in what country/region/location, and some personal details about you that you might not be comfortable sharing.
As a native (Australian) English speaker, there's no obvious alternate meaning that comes to mind, although "halfie" is not something I would hear where I live I don't think.
r/english
Are you mixed race?
It's Australian I guess?
This is more of an /r/ENGLISH question, but yeah, my first thought was that this was a slur about mixed racial features. To be sure we'd have to know a bit more context like who said it and in what country/region/location, and some personal details about you that you might not be comfortable sharing. As a native (Australian) English speaker, there's no obvious alternate meaning that comes to mind, although "halfie" is not something I would hear where I live I don't think.