Six
An Irish republican is a nationalist who supports the unification of Ireland and historically justifies the use of violence to achieve these ends.
Not quite, 'historically' or even today.
An Irish Republican is a supporter of a republican form of government in Ireland, and this was the case long before there was a whisper of Partition. This is what the Irish Civil War was all about - the republican ideal was not fulfilled by the Treaty that set up the Free State, with a Governor General, and the Monarch as head of state. The Republican idea was that authority rested in the people, as opposed to authority emanating from the Monarch, via Parliament.
After Partition, Irish Republicans except for a small minority coexisted quietly with the existence of NI, while paying a certain amount of lip service to the idea of a 32 county republic, with Irish cultural institutions operating on an all-Ireland level (the GAA for instance, and Rugby Union) and also the Church of Ireland and the RC Church, both of which have Armagh as the seat of their respective primates.
By the time the RC population of NI was inspired by the American Civil Rights movement to protest the apartheid system they were facing, the idea of unification had been dormant for a long time. It was resurrected in the early 70s by several groups including the Provos, INLA, etc., but it was still a minority position that violence was an acceptable means of reunification, while a majority of people in both states on the island continued to call themselves Republicans and eschewed violence even though the 70s saw the presence of British troops on the streets of NI and a very dirty war fought.
All through the Troubles the SDLP was the most popular party in the RC community in NI. The SDLP never called for violence as a means of problem solving but always had reunification as a plank of its platform. It was only after the Provo ceasefire in 1994 that the RC community in NI started to vote for SF, which also has reunification as part of its platform. Nationalist/RC people in NI support reunification and always have, especially when there is a chance that the goal is achievable and more to the point, when it looks as if the alternative - accepting the status quo and making the most of it - will never guarantee civil rights and equal justice. The GFA held out the hope that a guarantee of rights was going to be real and enduring and that a foundation of inter-community trust could be built. That is now a forlorn hope.
Which brings us to the utterly disgraceful behaviour of Theresa May, toadying up to the DUP, who are doing exactly what I suspected they would - wallowing in their own crapulence, indulging in offensive triumphalism, and apparently determined to eliminate republican political representation, i.e. political representation of almost half the population of NI by cutting off funding (where before they managed this by blatant and shameless gerrymandering of constituencies both local and national from 1922 on, with Westminster turning a blind eye.)
I suspect that a major say in redrawing of constituencies will be part of what the DUP demands, because gerrymandering makes everything look nice and legal.