Real Dictionary

generation
the act or process of bringing into being; production or reproduction, esp of offspring [...]
the continuous passage of existence in which events pass from a state of potentiality in the future, through the present, to a state of finality in the past [...]
adjective: Generation is used to indicate how long members of your family have had a particular nationality. For example, second generation means that you were born in the country you live in, but your parents were not.
countable noun: A generation is all the people in a group or country who are of a similar age, especially when they are considered as having the same experiences or attitudes.
countable noun: A generation is the period of time, usually considered to be about thirty years, that it takes for children to grow up and become adults and have children of their own.
countable noun: You can use generation to refer to a stage of development in the design and manufacture of machines or equipment.