{"era":"current","word":"sustainability","meaning":"The ability to be maintained at a certain rate or level.","children":[{"era":"1970s","word":"sustainable","meaning":"able to be maintained","children":[{"era":"1300s","word":"sustain","meaning":"to keep in existence","children":[{"era":"pre-1100","word":"sustenir","meaning":"to hold up, support","children":[{"era":"classical","word":"sustinere","meaning":"to hold up, to support","children":[{"era":"classical","word":"sub-","meaning":"under","children":[],"language":"Latin"},{"era":"classical","word":"tenēre","meaning":"to hold","children":[],"language":"Latin"}],"language":"Latin"}],"language":"Old French"}],"language":"Middle English"}],"language":"Modern English"}],"language":"Modern English"}