Hard to say really, very different for different people. For the born and bred scousers I'd imagine LFC stands for local pride. It's quite obvious even though I'm not from Liverpool that much of the rest of England, especially the south, has a superiority complex when it comes to Liverpool. During the glory years of the 70s and 80s and to an extent last season after winning the CL, it was a massive 2 fingers to the rest, everyone else was jealous of what LFC achieved.
While winning the CL last season was probably the best day of my life, I can only imagine what it must have felt as a scouser on that day, it must have been 10 times better. For the guys who go to all the games travelling up and down the country supporting the team, LFC must basically be their life.
For me, I don't make it over to games anywhere near as much as I'd like, even tried moving over to Liverpool a few years back so I could make more games but it didn't work out. For me I suppose LFC is a passion, it hurts when we lose and it's amazing when we win and I'll never forget the first time I heard YNWA sung at Anfield