Is deglutition a synonym for mastication?

No, deglutition and mastication are not synonyms. They are related but distinct processes:

* Deglutition is the act of swallowing, which involves moving food from the mouth to the stomach.

* Mastication is the act of chewing, which involves grinding food with the teeth to break it down into smaller pieces.

Here's a simple analogy: Imagine eating a cookie. You masticate (chew) the cookie to make it smaller and easier to swallow. Then, you deglutition (swallow) the cookie down your throat and into your stomach.