Hmmm, we could try 'fascis', which is Latin for 'bundle', but it's probably too close to 'fascism' for comfort. The diminutive 'fasciculus', 'small bundle' rhymes with 'ridiculous', so that's probably out as well
Then there's 'sarcina' (which rhymes with 'vagina', to remind us of the homologies), meaning 'package, perhaps a troublesome package'. That certainly fits. Or there's 'scruta', which means 'baggage, or junk', and might seem to better apply to the backside, but it's from the same root as 'scrutinize'--the 'package' is certainly scrutinized, by all and sundry...Finally, I don't think it's attested, but the form 'masculum' could be taken to mean 'the male thing': apparently, engineers use 'masculus' to refer to a 'male connector' in plumbing and electrical work. 'Masculum' would be a neuter noun, but then so is 'pudendum' (which by the way means 'the modest or shameful thing': probably not the best word in today's framework.)
Modern Greek has 'phortos', which means 'load', or 'desme', (two syllables rhyming with 'says me'), meaning 'bundle'.
I too wonder why there isn't such a term already. There are lots of candidates to choose from.