Geisha: Monk Weapon?

[Distant Scholar]

For the geisha bard archetype, what is a "monk weapon"? Is it a weapon a monk gets proficiency in? Is it a weapon with the "monk" special ability? Either? Both? Something else?

Can a geisha choose a hand axe as her weapon? (Monks are proficient, but it doesn't have the "monk" ability.)

Can a geisha choose a butterfly sword? (It has the "monk" ability, but monks apparently aren't automatically proficient.)

[blackbloodtroll]

In this case, it is any weapon described as a monk weapon within the weapon section.

[Ævux]

While I might be shooting in the dark here, I believe its weapons that have the monk special ability.. as they can be used in flury of blows.