{"era":"current","word":"concentration","meaning":"The action or power of focusing one's attention or mental effort.","children":[{"era":"1600s","word":"concentrate","meaning":"to gather into a center","children":[{"era":"1500s","word":"concentrare","meaning":"to bring to a common center","children":[{"era":"classical","word":"con-","meaning":"together","children":[],"language":"Latin"},{"era":"classical","word":"centrum","meaning":"center","children":[],"language":"Latin"}],"language":"Medieval Latin"}],"language":"English"}],"language":"Modern English"}