In a manner that joins or unites things together; with tendency to combine or fuse.
From coadunative + -ly (adverbial suffix). Creates the adverbial form from the adjective, following standard English adverbial formation.
This is about how rarely we actually need adverbs this specialized—you'd almost never hear 'The tissues grew coadunatively,' yet the word exists, showing English's remarkable capacity to build specific technical vocabulary.
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