A person who must always be addressed by both their first name and last name. Either they are one of many who share the same first name or it simply sounds weird if someone addresses them by only their first name.
John Smith? He's a firstie lastie, nobody calls him John without saying Smith as well.
The word you use when you are talking about something that happened in the recent past, but you can't remember the exact day (due to a black out), or it really doesn't have any significance to the story...or you just can't be bothered to think hard enough to remember it.
Amber: I just went to a Ween concert in Anaheim.
Penny: Really, when was that?
Amber: Lasterday, I think.
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.