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".
