{"era":"current","word":"unthinkable","meaning":"impossible or extremely hard to imagine","children":[{"era":"pre-1100","word":"un-","meaning":"not; opposite of","children":[],"language":"Old English"},{"era":"pre-1100","word":"think","meaning":"to form an idea or opinion in the mind","children":[{"era":"pre-1100","word":"þencan","meaning":"to think","children":[],"language":"Old English"}],"language":"Old English"},{"era":"1200s","word":"-able","meaning":"capable of; fit to be","children":[],"language":"Middle English"}],"language":"Modern English"}