LANCER is derived from the English word "lancer", which means "a cavalryman armed with a lance".
EVOLUTION is derived from the English word "evolution". The popular name is often called "LANEVO".
The generations of LANEVO are commonly called as 1st : I to III, 2nd : IV to VI, 3rd : VII to IX, 4th : X. LANEVO I (One) was initially planned to sell as a limited model, so the official car name was "LANCER EVOLUTION" without I (One). Since the launch of LANEVO II, the first model was naturally called as "LANEVO I".