tertium quid
noun
ter·ti·um quid ˌtər-shē-əm-ˈkwid 
ˌtər-tē-
1
: a middle course or an intermediate component
where there are two systems of law and two orders of courts, there must … be some tertium quid to deal with conflicts of law and jurisdiction
Ernest Baker
Ernest Baker2
: a third party of ambiguous status
there was a man and his wife and a tertium quid Rudyard Kipling
Rudyard Kipling
Word History
Etymology
Late Latin, literally, third something; from its failing to fit into a dichotomy
First Known Use
circa 1724, in the meaning defined at sense 1
- friction slip
- friction socket
- friction sound
- friction tape
- friction top
- friction wheel
- friction-glazed
- friction-tight
- frictional
- frictional gearing
- frictional unemployment
- frictionally
- frictionize
- frictionless
- frictionlessly
- frictions
- Friday
- fridays
- fridge
- fridge-freezer
- fridges
- Fridley
- fridstool
- frie
- fried