Someone who applies scientific knowledge to any problem. Has a common tendency to over-complicate simple solutions, see Rube Goldberg.
Enginerd: So, if we apply the Brownian theory of molecular movement, we can determine exactly how hot your syrup is, and how hot is *NEEDS* to be can be found by applying...
Mundane: Seriously, why'd you have to get all enginerd about it? Just use a thermometer.
A person who uses scientific knowledge to solve practical problems, and is felt to be socially inept. This person can also portray symptoms of a large ego, knowledge of too many keyboard shortcuts, and overall addiction to his/her computer. Most are in denial of their 'enginerdiness'.
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.