Final answer:
The word that means the same as 12 o'clock at night is midnight.
Step-by-step explanation:
The word that means the same as 12 o'clock at night is midnight.
In our timekeeping system, we designate the hours before noon as 'ante meridiem' (a.m.) and the hours after noon as 'post meridiem' (p.m.). The Sun is said to be 'passing meridian' at noon.
So, the correct answer to your question is 2) Midnight.