How do you do is a very formal greeting used on first meeting somebody. How do you do, said with a handshake.
It is not a question, and the correct answer is to say how do you do straight back. It is now rare and sounds old-fashioned or careful, so most people say pleased to meet you instead.
1phrasehow do you doA very formal greeting used on first meeting somebody.
“He put out his hand and said how do you do.”
how do you do is a greeting.
Practised in Small Talk & Everyday Phrases