According to Wikipedia:
Ho is a town in southeast Ghana and is the capital of the Volta Region.

With that out of the way, another definition that sees more use in the American vernacular. From wiktionary:

A whore; a sexually loose woman; in general use as a highly offensive name-calling word for a female with connotations of loose sexuality.

Finally, I'd like to draw your attention to the apparent prescience of Webster 1913, where the first line for this word reads:

Ho (?), pron.

which presages both a modern alternative spelling of "pornography" and the association of prostitution with this industry sector.