UK:*UK and possibly other pronunciationsUK and possibly other pronunciations/sʌbˈdʒɔɪn/US:USA pronunciation: respellingUSA pronunciation: respelling(səb join)

WordReference Random House Unabridged Dictionary of American English © 2020
sub•join  (səb join),USA pronunciation v.t. 
  1. to add at the end, as of something said or written;
  2. to place in sequence or juxtaposition to something else.
  • Middle French subjoindre. See sub-, join
  • 1565–75

Collins Concise English Dictionary © HarperCollins Publishers::
subjoin /sʌbˈdʒɔɪn/ vb
  1. (transitive) to add or attach at the end of something spoken, written, etc
Etymology: 16th Century: from French subjoindre, from Latin subjungere to add to, from sub- in addition + jungere to join

subˈjoinder n
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