Are the words "merge" and "separate" antonyms or synonyms?
The words "merge" and "separate" are antonyms, in that the meaning of one is the opposite of the meaning of the other.
Merge means to put together as in two roads merging into one or two companies merging.
To separate means to take apart, which results in the opposite effect.
Another antonym for merge is "de-merge", which is a synonym for separate.