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.