A word made up by people uneducated in the ways of etymology. NOT THE PLURAL OF PENIS.
The rule with aplural form
with an I is derived from latin and is only
applicable when the word ends in -US, and has no relevance whatsoever when the word ends in -IS.
When a word ends in -IS, the correct plural form is, in fact, -ISES.
(US-I)
The Octopus was
languid.
The Octopi were languid.
The radius was 5cm long.
The
radii were both of the same length.
The Hippopotamus was huge.
All the
hippopotami were huge.
(IS-ISES)
Within most species the penis is used for reproduction.
The correct plural or penis is penises, not penii.
The White Ibis is my favourite of all the Ibises.
