To Flock
To Crowd, To Swarm
intransitive verb, ichidan verb
Remember how 群れ is a flock? This is the verb version, and means to flock or to crowd together with a bunch of other people.
The reading is the same as 群れ, so if you know that you can flock together the two memories in your brain.
どうして日本では、不良少年少女は、コンビニの前で群れる傾向があるんでしょうか。
I wonder why delinquent kids tend to hang out in front of the convenience stores in Japan.