1. class (of students)
pronounced ぐみ as a suffix
この組の担任は田中先生だ。This class's homeroom teacher is Mr. Tanaka.
2. group (of people); party; team; crew
向こうの組には二人の女性がいる。There are two women in the group over there.
3. lot; bunch; set
4. crime family; organized-crime syndicate
警察が組の事務所にまで来たらしい。Apparently the police even came to the gang's office.
5. set (of items); assortment; deck (of cards); pack
下着は何組必要だろう。How many sets of underwear will I need?
6. typesetting; composition