to hold back: to linger, hesitate, or be slow in coming when it was time to move
Something is due to happen, and it has not happened yet. That is the whole idea of this verb. It can be a man frozen in a doorway while a city burns, a group of travelers sitting a little longer over a meal, or a promise that has not yet arrived. In every case the clock is running and someone notices.
What holds the shades together is the gap between the expected moment and the actual one. Sometimes that gap is a failing: Lot has to be taken by the hand and pulled out of Sodom because he will not move (Genesis 19:16), and the writer of Psalm 119 boasts of the opposite, hurrying to obey without losing a minute (Psalm 119:60). Sometimes it is harmless or even chosen: a father presses his guests to stay on through the afternoon (Judges 19:8), and David decides to hold at the desert crossings until word reaches him (2 Samuel 15:28).
The heaviest use turns the word on God's own timing. In Habakkuk 2:3 the vision has a set moment, and the prophet is told that even if it seems slow, he should wait for it, because it will not miss its appointment. Two neighboring words sit in that same verse: the command to wait for it (חָכָה) and the promise that it will not be late (אָחַר). The Greek New Testament picks the promise up with its own verb for being overdue (χρονίζω) when Hebrews 10:37 quotes it.
The word never simply names the passing of time. It always measures time against something that was supposed to happen, which is why English needs several different words to carry it from one scene to the next.