" The term "The Great Tribulation" comes from Revelation 7:14."
Well "John" here is using the same expression that we find put in to the mouth of Jesus by the Synoptic Gospel Writers, in Matt. 24 and Mark 13. These being written earlier than Revelation, "John" would be familiar with them.
More interesting is to read the context of the Synoptic's words around this expression in the Olivet Discourse. Read as an unbiased Academic would, not a Believer. Take those "Believer's Specs" off !
It is plain to see if you read the "words of Jesus" here, that he is claiming that he would return in the lifetime of his listeners.
Another failed Biblical Prophecy.