v.1. To keep something from falling apart: The paper clip held together the memos. The rubber band held the manuscript together.
2. To remain functional and whole: I'm surprised that old car is still holding together so well. I hope this computer holds together until I can afford a new one. My family has managed to hold together through some tough times.
3. To maintain one's composure. Used reflexively: Hold yourself together. He held himself together after the accident.
4. To be logically sound: Your explanation doesn't really hold together.