The phrase "a third age" is correct and usable in written English.
It can be used to refer to a distinct period in life, often associated with older adulthood or a specific phase in a person's life or society.
Example: "As we enter a third age characterized by increased longevity, we must rethink our approach to retirement and active living."
Alternatives: "a new phase" or "an additional era".
That's because we're now in a third age of smartphone buying.
The Spiritual Franciscans at mid-13th century and various other friars, monks, and sects down to the 16th century appropriated his prophecy of a third age.
Retirement for them will be a third age, still full of assorted activities.Why they keep growingDemographics partly explains the growth of planned communities.
The purpose of this study was to examine the prevalence of depressive symptoms above the elderly participants of a Third Age Open University, taking the time taking part as a reference.
The concept of wirelessness has proved to be such a hit with consumers that a third age of cord cutting has dawned, in which the benefits of going wireless are not always immediately clear.
From encyclopaedic "cabinets of curiosity", to echoing cathedrals for the larger-scale work (and reputations) of artists, museums are now entering a third age as collaborative spaces, where artists, audiences and curators interact in the co-production of culture and value.
First, a new stage of life awaits us--a third age, you might say--after childhood and middle age but before the last years of life.
In everyone else's view, Lovey was lucky to have got out before her older husband became like a third aging parent, before the inevitable illness and decline.
Both groups each included a third, age-matched calf as an environmental control, which was not inoculated: Aberdeen Angus crossbred heifer CO3 for the H-type BSE inoculated cattle and Holstein Friesian steer CO4 for the L-type BSE inoculated cattle.
Today's octogenarians were brought up in the days when the biblical sell-by date remained in place; we looked forward to a seventh age of slippered pantaloonery, but find ourselves instead in an eighth age of dribbling dementia.
It marked the passing of a first age of globalisation that had flourished in the decades before the first world war with free movements of capital, freedom and – to a lesser extent – goods.
