1. The people born and living about the same time, considered as a group: the baby-boom generation.
2. The average interval of time between the birth of parents and the birth of their offspring: a social change that took place over three generations.
3. All of the offspring that are at the same stage of descent from a common ancestor: Mother and daughters represent two generations.
4. Biology A form or stage in the life cycle of an organism: the asexual generation of a fern.
a. A stage or period of sequential technological development and innovation.
b. A class of objects derived from a preceding class: a new generation of computers.
6. The formation of a line or geometric figure by the movement of a point or line.
7. The act or process of generating; origination, production, or procreation.
8. Physics Any of three groups of fundamental fermions, each containing two quarks and two leptons, together with their associated antiparticles, corresponding members of which differ in mass and lifetime. The first or electron generation consists of the down quark, up quark, electron, and electron neutrino lepton. The second or muon generation consists of the strange quark, charm quark, muon, and muon neutrino lepton. The third or tauon generation consists of the bottom quark, top quark, muon, and muon neutrino lepton.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.