consummation (n.) Look up consummation at Dictionary.com
late 14c., "completion," from Latin consummationem (nominative consummatio), from consummat-, past participle stem of consummare "to sum up, finish," from com- "together" (see com-) + summa "sum, total," from summus "highest" (see sum (n.)). Sense of "completion of a marriage (by sexual intercourse)" is c.1530.