Russian President Vladimir Putin speaks during a nationally televised question-and-answer session in Moscow on Thursday, April 17, 2014. Russian President Vladimir Putin on Thursday rejected claims that Russian special forces are fomenting unrest in eastern Ukraine, but recognized for the first time that the troops in unmarked uniforms who had overtaken Ukraine's Crimean Peninsula before its annexation by Moscow were Russian soldiers. (AP Photo/RIA Novosti, Alexei Druzhinin, Presidential Press Service)

A casual listener may have missed it, but many Ukraine-watchers raised their brow when Russian President Vladimir Putin used the weighty term "Novorossiya" or "New Russia" to refer to some regions in Ukraine on Thursday. "It's new Russia," Putin told the audience during his nearly four-hour long televised Q&A. "Kharkiv, Luhansk, Donetsk, Odessa were not part of Ukraine in czarist times, they were transferred in 1920. Why? God knows."

To give you a little background, "Novorossiya" is an archaic term for an area that was controlled by Russia during the imperial czarist times of the 19th century. In The New Republic, Linda Kinstler explains that the name referred to "the formerly Ottoman territory that Catherine the Great conquered in the Russo-Turkish Wars," an area that is mostly comprised of what is now southern and eastern Ukraine.

When Putin chose to use this specific term to describe Ukraine's east on Thursday, many worried he was openly embracing the notion of an old imperial Russia, one which held control over what is now a sovereign country.

But Putin hasn't been the only one taking up the term recently. Rather, the president played into the slogans pro-Russia activists in eastern Ukraine have been chanting in recent weeks.

Reporting from Eastern Ukraine for Foreign Policy, Christian Caryl writes that some of the protesters in the region have been using the term "Novorossiya" to refer to an autonomous region they want to create, one with strong Russian allegiances. Caryl adds that given the importance of these regions for the Ukrainian national economy, such a move would be a gigantic blow to the already cash-strapped government in Kiev.

In order to really understand why the use of "Novorossiya" is causing many to take note, it's also helpful to understand one more term: Irredentism. As political scientist Stephen Saideman defines it, "irredentism is the effort to reunify a 'lost' territory inhabited by ethnic kin with either a mother country or with other territories also inhabited by ethnic kin."