A small item of everyday personal luggage, similar in size to a woman's purse except intended for use by a man, smaller than a briefcase or attache, carried by hand or by a shoulder strap (not belted nor belt-looped), and typically distinguishable from a woman's purse by having a tall, narrow, rectangular form-factor, rather than the short and wide shapes more typical of most women's purses.
"Let me gift-wrap this man-purse for you to present to that special gentleman, ma'am, since obviously a respectable woman like yourself wouldn't purchase such a masculine item for herself." (-paraphrased actual remark of a female shopkeeper in Amsterdam to an American shopper buying a tall, narrow purse)
A over the shoulder bag worn by men who live in the more urbanized areas. Not all that popular in America because the unfortunate holder of the bag will most certainly be picked on, whispered about or deemed the honourary 'fag of the day' but far more common in the European nations (especially France) where people aren't so silly and suspicious of doing things that will make them seem fruity.
American: Hey, is that a man purse!? Ha ha! You're the honourary fag of the day!