• mey group,
• ley group,
• oey group,
• iey group,
• kwy group,
• ksy group,
• kdy group,
• kry group,
• k4y group,
• k3y group,
• keg group,
• keh group,
• keu group,
• ke7 group,
• ke6 group,
• key froup,
• key vroup,
• key broup,
• key hroup,
• key yroup

The adjective form of "key group" is "key".

The plural form of the word "key group" is "key groups"

The singular form of the word "key group" is "key group". In English, most nouns do not change their form when they are used in the singular or plural.