What is the synonym of salutation?

Here are some synonyms for salutation, depending on the specific context:

Formal:

* Greeting

* Address

* Compliments

* Regards

* Respects

Informal:

* Hello

* Hi

* Howdy

* Greetings

* Cheers

Other:

* Welcome

* Acknowledgement

* Introduction

The best synonym to use will depend on the specific situation and the level of formality you are aiming for.