Usage patterns
〈場所〉の人込みに紛れるto blend into / disappear in a crowd
He disappeared, blending into the crowd at the station.
人込みを避けるto avoid crowds
I try to go out avoiding crowds on my days off.
人込みで〈人〉とはぐれるto get separated from someone in a crowd
I got separated from my child in the crowd at the festival.