Zayd bin Aslam (may Allah have mercy on him) narrates it in the same way, but without the words: "al-madha' means the dayyuth, the one without ghayrah." Abu Ubayd (may Allah have mercy on him) explains that al-madha' is taken from al-madhy; what is meant is gathering men and women together and then letting them mix, so that they behave shamelessly with one another.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 21024