to add (something) at the end of what has been stated; append
Origin of subjoinMiddle French subjoindre from Classical Latin subjungere: see sub- and join
transitive verbsub·joined, sub·join·ing, sub·joins
To add at the end; append.
Origin of subjoinObsolete French subjoindre from Latin subiungere sub- sub- iungere to join ; see yeug- in Indo-European roots.