The word ”sustain” comes from the Latin sustinere, which means "hold up, hold upright; furnish with means of support; bear, undergo, endure". Sustinere is made up of the root word sub "up from below" + tenere "to hold". (source)
In their 1987 report “Our Common Future,” the UN’s Brundtland Commission defined, “Sustainable development” as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.
Triple bottom line
Profit is a traditional measure of corporate success, usually referred to as the bottom line. In 1994 John Elkington coined the term the “triple bottom line” (TBL). It adds social and environmental responsibility to how organisations conduct their activities. It has since become a method of measuring sustainability. (source)
Urban Digestor’s Triple Bottom Line for Sustainable Outcomes
People - Human beings have needs. Like Maslow, we recognise that these needs go beyond the physical. We all need supportive environments to be able grow as emotional and spiritual individuals and communities.
Planet - Our planet provides us with a place to dwell and the resources to create our livelihood. Our activities need to respect the natural world that surrounds and supports us.
Prosperity- To prosper means to thrive and succeed in a healthy way. (source) Our activities must create outcomes that contribute to our own prosperity and the prosperity of the global community.
So we see being sustainable as supporting our planet and the global community that supports us. The triple bottom line of People, Planet & Prosperity is not just an ethical stance but a practical approach to business and design.