A school class (e.g., '1st-year, class 2'); when used as a suffix it can be pronounced ぐみ.
うちの子は今年3年2組になった。
My child is now in 3rd year, class 2.
2組は教室で発表の準備をしている。
Class 2 is preparing their presentation in the classroom.
A group of people; a party, team, or crew.
彼はいつも三人組で学校に来る。
He always comes to school with a group of three.
探偵チームの組が現場に向かった。
A detective team went to the scene.
A lot, bunch, or set — a grouped collection of items.
皿を一組揃えて新居に持って行った。
I took a set of dishes to my new home.
楽器は三組に分けて運ぶことになった。
The instruments were divided into three sets for transport.
A crime family; an organized-crime syndicate (e.g., yakuza group).
その事件は組の抗争が原因とみられる。
That incident is believed to have been caused by a gang feud.
警察は暴力団の主要な組を摘発した。
The police cracked down on a major crime syndicate.
A set or assortment of items (e.g., a deck of cards; a matched set).
トランプを1組買ってきてください。
Please buy one deck of playing cards.
食器は一組ずつ箱に入れて保管する。
Put each set of tableware into a box for storage.
In printing, typesetting or composition — arranging type and layout (a technical term).
組版の作業は細かい調整が必要だ。
Typesetting work requires fine adjustments.
組版ソフトを使って見出しを整えた。
I adjusted the headings using typesetting software.