Green’s Dictionary of Slang

afro n.

also ’fro
[abbr.]

1. [1930s; 1960s+] (orig. US black) a black hairstyle in which normally short, curly black hair is allowed to grow out in a bush around the head, supposedly in the style of one’s African forebears; also occas. used of white people’s hair; thus afro-style, having an afro hairstyle.

2. attrib. use of sense 1.

3. [1930s–70s] an English or American person of African descent, a black.