The famous Littré dictionary (four volumes, 1880s) provides the following definition of souteneur:
2 Particulièrement, celui qui se fait le champion d'une maison de jeu ou de quelque mauvais lieu. Un souteneur de filles.
Free translation:
Particularly, someone who acts as the champion/defender of a gambling house or some house of ill repute. A souteneur of "girls".
(I have left "souteneur" untranslated to keep the circularity of the definition.)
Volume 3 of the same dictionary defines proxénète as follows:
2 Aujourd'hui, en mauvaise part, entremetteur de certains marchés honteux entre les deux sexes.
Translation:
Today, in a negative sense, matchmaker/procurer for certain shameful deals between the two sexes.
Delvau's Dictionnaire de la langue verte (literally "dictionary of green language", i.e. argot) defines souteneur as follows:
Homme qui vit aux dépens des filles, — dans l'argot du peuple.
Translation:
Man who lives at the expense of girls, — in popular argot.
This dictionary has no entry for "proxénète",
although the term is used in entries for other terms (see lanceuse and
ogresse, a "madam").
Delesalle's Dictionnaire Argot-Français & Français-Argot (1896) provides the following definition of souteneur:
Celui qui vit aux dépens des prostituées, et qu'on appelle ainsi parce qu'il est censé les soutenir quand elles sont instultées.
Translation:
He who lives at the expense of prostitutes and who is called this [i.e. souteneur] because he is supposed to support them when they are insulted.
The dictionary entry for "proxénète" says "Voy. Entremetteur" (See "entremetteur"); the entry for "entremetteur" says "Voy. Proxénète. Voy. Rouspant, Dariolet, Dariolette, Eléphant".)
Wiktionnaire provides the following definition of souteneur:
Celui qui, vivant du gain d’une prostituée, prétend assurer, en retour, sa protection.
Translation:
He who, living from the gains of a prostitute, claims to protect her in return.
The aspect of protection is mentioned by Littré but not by Delvau.
Wiktionnaire defines proxénète as follows:
Personne qui tire profit de la prostitution d’autrui ou bien la favorise.
Translation:
Person who profits from the prostitution of another person or furthers it.
The definition does not state whether a proxénète is male or female, but quotes a sentence from Proust that illustrates that it could be a woman ("mais il l’aimait comme une proxénète").
Finally, Virmaitre's Dictionnaire d'argot fin-de-siècle (1894) provides the following definition of proxénète:
Proxénète: Ou maquerelle; c'est la même chose.
La proxénète est à l'affût de toutes les misères pour livrer les malheureuses à la prostitution.
Translation:
Proxénète: Or madam; it's the same thing.
And souteneur:
Souteneur: Individu qui vit des filles qui se livrent à la prostitution, fainéant, voleur et assassin si l'occasion se présente; on le trouve en haut comme en bas de l'échelle sociale (Argot du peuple).
Translation:
Individual who lives off girls who prostitute themselves; idler, thief and murderer if the opportunity presents itself; found both at the top and at the bottom of the social ladder (People's argot).
In summary, we have the following:
- A proxénète is a woman according to Virmaitre, and can be a woman based on Delvau and Wiktionnaire. Littré provides no information on this matter.
- A souteneur is a man (in fact, the ending eur already suggests this), who, according to Littré, Delesalle and Wiktionnaire, provides "protection" (the quotes are mine) while living of the gains made by prostitutes. The aspect of protection is not mentioned by Delvau and is at best ambiguous in Virmaitre.
