Word: extradyadic

[ADSGarson O'Toole]

The word "extradyadic" is not in the OED. The OED does have "dyadic"
listed with a technical definition. I have not looked for early
examples. This post just gives evidence of use in popular culture.

Website: Newsweek
Title: Wall Street Loves a Cheater
Subtitle: As a site serving adulterers booms, big financial firms start circling
Author: Lynnley Browning
Date: October 11 2013 (Looks like the article has been posted early)
http://mag.newsweek.com/2013/10/11/wall-street-loves-a-cheater.html

[Begin excerpt]
Still, selling shares in an Internet company (even a profitable one)
devoted to something sociologists term "extradyadic behavior" and the
rest of the world calls "cheating on your spouse" isn't easy. Ashley
Madison has been banned from global advertising by Facebook, which has
an app called Bang With Friends, and even by Japan, the land of
massage parlours and "hostesses."
[End excerpt]


Website: The Sydney Morning Herald
Blog name: CityKat
Article title: Extradyadic sex - cheating or just fantasising?
Date:April 10, 2013
Author: Katherine Feeney
http://www.smh.com.au/lifestyle/life/blogs/citykat/extradyadic-sex--cheating-or-just-fantasising-20130409-2hjc2.html

[Begin excerpt]
Is it wrong to think about someone else when you’re having sex?

There are reams of scientific paper dedicated to a subject called
“extradyadic sex”.

What is it exactly?

According to the Encyclopedia of Human Relationships, the term refers
to a wide range of behaviours occurring outside of a committed
relationship, though (probably because most academic research is
carried out by men) it’s most commonly understood as vaginal sex
outside of marriage.
[End excerpt]

OED dyadic, adj. and n.
Draft additions  1993
Forms:  Also (rare) diadic.
  Logic. Pertaining to or designating a relation between exactly two
entities, or a predicate expressing such a relation. Also used
transf., esp. in Math. and Computing, to designate any expression,
operator, etc. which requires or acts on two arguments.

1897   C. S. Peirce in Monist VII. 167   An ordinary relative with an
active verb as ‘—is a lover of—’ or ‘the loving by—of—’ has two
blanks; it is a dyad, or dyadic relative.

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