B1[C, + sing/pl verb]all the people of about the same age within a society or within a particular family: The younger generation smoke/smokes less than their parents did.There were at least three generations - grandparents, parents and children - at the wedding.It's our duty to preserve the planet for future generations.This painting has been in the family for generations.Ancestors and descendantsGroups of peopleB2[C, + sing/pl verb]a period of about 23 to 30 years, in which most human babies become adults and have their own children: A generation ago, home computers were virtually unknown.Specific periods of timefirst, second, third, etc. generation›describes the nationality of someone belonging to the first, second, third, etc. group of people of the same age in the family to have been born in that country: She's a second-generation American (= her parents were American, although their parents were not).Ancestors and descendants