tertium quid /tûrˈsh(i-)əm kwid or terˈti-ŭm/)

1. A third unknown thing related to two specific known things
2. Something intermediate between opposites
3. The third person in the eternal triangle

• square-bashing
• square bracket
• square brackets
• square-built
• square centimetre
• square-cut
• squared
• square dance
• square-dance
• square danced
• square-danced
• square dances
• square-dances
• square dancing
• square-dancing
• squared circle
• squared circles
• square deal
• square deals
• square-eyed
• square eyes
• square-face
• square feet
• square foot
• squarehead