to leave a person or thing behind and go on without it, so that what is left stays where it is
Picture someone packing for a journey. Whatever does not go along is set down and stays put, still there after the traveler has gone. That is the picture inside this verb: not throwing a thing away, but going on without it. Paul uses it exactly that way in his last letters, leaving a cloak with a friend at Troas, leaving a sick companion behind at Miletus, and leaving Titus on Crete with a job to finish.
The same verb can be turned around to describe not the act of leaving but what has been left, and that is where Hebrews builds an argument on it. If God promised a rest and the first hearers never entered it, then the rest is still lying there unclaimed, so a sabbath rest is left for the people of God. Put the same wording in the negative and it becomes a warning: for someone who goes on sinning deliberately after knowing the truth, no sacrifice is left.
The third use is the darkest, and it is the same act aimed at something a person had no business leaving. In Jude 1:6 the angels leave behind the home that was properly theirs. The word is not a technical term for rebellion; it is the ordinary word for walking off and not coming back. What makes the sentence terrible is what they walked away from, not the verb.
Titus 1:5 shows that the writers heard the wordplay. Paul left Titus on Crete so that Titus could set right what had been left undone, the shorter verb for falling short (λείπω) standing right beside the longer one built from it.