{"era":"current","word":"unavailable","meaning":"not accessible","children":[{"era":"pre-1100","word":"un-","meaning":"not","children":[],"language":"Old English"},{"era":"1400s","word":"available","meaning":"able to be used","children":[{"era":"1200s","word":"availler","meaning":"to be of use","children":[{"era":"1200s","word":"a-","meaning":"to","children":[],"language":"Old French"},{"era":"1200s","word":"valoir","meaning":"to be worth","children":[{"era":"classical","word":"valere","meaning":"to be strong, be worth","children":[],"language":"Latin"}],"language":"Old French"}],"language":"Old French"}],"language":"Middle English"}],"language":"Modern English"}