An attempted humorous pluralization of the word "penis". As with other words from Latin that end with "is", such as "crisis" and "
neurosis", "penis" changes the "is" to "es", forming "penes", as "crisis" changes to "crises" and "
neurosis" to "neuroses". Only urologists and a handful of other
professionals use the word "penes", however, so it is best to stick to the English plural, "pensises".