Later and So long

Later adjective - Being, occurring, or carried out at a time after something else.

So long and later are semantically related. In some cases you can use "So long" instead the word "Later" as a noun or a interjection.

So long noun - A farewell remark.

Later and so long are semantically related. Sometimes you can use "Later" instead the phrase "So long" as a noun or a interjection.