General:
* Introduction: This is the most common and direct noun, referring to the act of introducing something or someone.
* Presentation: This implies a more formal or public introduction.
* Presentation: This is similar to "introduction", but often emphasizes the act of revealing information or ideas.
Specific situations:
* Induction: This refers to the act of introducing someone to a new position or role.
* Initiation: This implies a formal or ceremonial introduction, often into a group or organization.
* Familiarization: This refers to the act of making someone acquainted with something.
* Exposure: This implies a brief or casual introduction.
Other options:
* Overture: This is more literary and refers to an introductory statement or action.
* Preamble: This implies an introduction that sets the stage for something else.
The best noun to use will depend on the specific context of your writing or speech.