1. groups of people related by blood, marriage, or adoption who live together or are closely connected
Usage: plural of family
2. groups of related plants, animals, or other things that share common characteristics
Usage: scientific classification; plural of family

Examples

• Many families gather together for holiday celebrations.
• The neighborhood has several young families with small children.
• Both families approved of the marriage.
• Military families often move frequently due to deployments.
• The rose and apple belong to different plant families.
• Scientists study various families of marine animals.
• These languages belong to the same linguistic families.