Gathering, Meeting, Assembly, Party, Collection, Get Together
noun
This is the noun version of the kanji gather, so it means gathering.
あつまり
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You learned this reading already so you should be able to read it!
今日は研究室の集まりがある。
There’s a get-together with people from the lab today.
なんか今日のパーティー、集まりも悪かったし、グダグダだったね。
Not many people showed up at today's party and it was also very disorganized.
正月の集まりに弟がガールフレンドを連れてきやがった。
My younger brother brought his girlfriend to our New Year's gathering.