A good host introduces their guests. But even the best host sometimes forgets names.
If you can see this happening to your host, usually indicated by a slight pause followed by a look of panic, jump right in. Take over the introduction. Put your hand out, say your name, and ask who you have the pleasure of meeting.
Nine times out of ten, if one of the people being introduced takes the initiative, the other person will reciprocate with their name unprompted. It saves your host, who’ll love you for it, and hey, you’re one sentence closer to actually making a decent connection with whoever you’re meeting.
Don’t be lazy about meeting people. Always be ready to jump in with introductions. It’s better for everyone that way.