Noun.
Description of
the state of times before or after noon in the 12-hour clock. Can be either ante meridiem (A.M.) or post meridiem (P.M.)
The term meridiemem was first defined and used in Chicago, on Oct. 20th 2011 by Benjamin
Michael Brown, Piotr Bieszk, and Shavar Beckford.
Q: Which meridiemem describes
the time before noon?
A: The "AM" meridiemem describes
times before noon. The meridiemem "PM" describes
times after noon.