joinder (plural joinders)

1. (legal) The joining of a litigant to a suit.
2. The act of joining; a putting together; conjunction.
   • c. 1601–1602, William Shakespeare, “Twelfe Night, or VVhat You VVill”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act 5, scene 1]:

     A contract of eternal bond of love, Confirm'd by mutuall ioynder of your hands.