To Flock, To Crowd
intransitive verb, godan verb
Remember 群れる, which means "to flock" or "to crowd."? This also means that!
むらがる
The reading is a little different from 群れる, though. There's an extra ら in there. That being said, it's pretty similar, so you should be able to use one to remember the other after a few reps. You can also think about it this way: Everyone is flocking together in one place. Strange thing is, it's to a small 村 (むら). There's a 村 reunion going on, that's why.
空港に到着するとファンが群がっていて、驚きましたよ。
We were surprised that fans had gathered to wait for us when we arrived at the airport.