1.
If you describe someone as tight-lipped , you mean that they are unwilling to give any information about something.
Military officials are still tight-lipped about when or whether their forces will launch a ground offensive.
≠ forthcoming
ADJ : oft ADJ about n / wh
2.
Someone who is tight-lipped has their lips pressed tightly together, especially because they are angry or disapproving.
He was sitting at the other end of the table, tight-lipped and angry.
ADJ