Today's word is one of my favourites, because being mean is so much more fun when you use words that the plebeians don't understand. :D
An unprofitable or useless science or skill.
From a Greek term combining 'vain' + techny, 'art'
1576 Newton Lemnie's Complex. To Rdr.,: Such a peevish practice, and unnecessary Matæotechny
We have a lot of young people at work, many of them born this side of 1990. These are the kinds of people that have never heard of Danger Mouse, Tin Tin or Asterix and Obelix, and give you a blank stare when you bring up Bob Dylan, Cat Stevens or ask them to name one Beatles song that isn't from White Album.
These people have a collection of most braggable Mataeotechnia, such as being able to drink copiously before vomiting, being able to find the best DJs (a loose term - better to call them 'Laptop With Winamp and Crossfade Jockeys') in town and being able to score the cheapest drugs.
And yet they call my ability to name the first 20 elements useless!
(apologies to late-era Generation Y'ers and Gen Z's - it's not your fault you aren't awesome Gen X'ers. ;)