How do we define terrorists?

There's a funny opinion from the maoist leader.

"The government should not hold dialogue with parties that want to split the country. They should be termed terrorists and strong action taken against them"

Terai extremists are terrorists: Maoist leader

Terrorists = those who want to split the country

Didn't he mean that?

According to Wikipedia, terroists or terrorism has the following key criteria

• Violence
• Psychological impact and fear
• Perpetrated for a Political Goal
• Unlawfulness or illegitimacy

Following that criteria, can somebody tell me why maoists shouldn't be put in that category? Or else we redefine the terrorist and terrorism, in Nepal's context. Why do people give their opinions without even going through the dictionary? Maybe they were never taught to.