matricide /māˈtri- or matˈri-sīd/

1. A murderer of his or her own mother
2. The murder of one's own mother

• at the crack of dawn
• at the double
• at the drop of a hat
• at the earliest
• at the eleventh hour
• at the end of one's tether
• at the end of the day
• at the expense of
• at the feet of
• at the first blush
• at the fore
• at the full
• at the hand of
• at the hands of
• at the head of the poll
• at the heels of
• at the instance of
• at the latest
• at the least
• at the mercy of
• at the most
• at the outside
• at the point of
• at the ready
• at the risk of