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

2

: a third party of ambiguous status

… there was a man and his Wife and a Tertium Quid

—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

Rhymes for tertium quid

• superfluid
• amid
• eyelid
• forbid
• majid
• outbid
• outdid
• plasmid
• turbid
• undid
• bid
• did