need help with this quiz question

[detective]

CIVIC DIM ILLICIT LIMPID MILL MINIM MIX VIVID

Which is the odd word out and why?

P.S It can't be anything to do with Roman Numeral letters because of the P and T

[Big Al1st]

Hi Detective, Probably not the answer but ILLICIT is the only word without an I as its second letter

[swannbaker]

Most of the letters here have symmetry if you can make a case for the L and the N , but clearly the P is asymmetric . But then again why hasn't the quizmaster used A , E , O and U . Using Big Al's argument , MILL is the only word without an I as it's second last letter . Back to the drawing board . Where does the question come from ?

[smouse]

on a previous answer it said that they were roman numerals but I coudnt find them