{"era":"current","word":"calendar","meaning":"system of organizing time into days and months","children":[{"era":"1200s","word":"calendar","meaning":"calendar, list of holy days","children":[{"era":"classical","word":"calendarium","meaning":"account book, calendar","children":[{"era":"classical","word":"calendae","meaning":"first day of the month","children":[],"language":"Latin"}],"language":"Latin"}],"language":"Old French"}],"language":"Modern English"}