biting and grinding food in your mouth so it becomes soft enough to swallow
"The baby spent most of his naptime chewing on a piece of carrot until it was soft enough to swallow."
The act by which something is chewed on; mastication.
"He spent all afternoon sitting in the corner, his only activity being chewing on a piece of gum he found under the table."
present participle of chew
"The dog kept chewing on his favorite squeaky toy until it finally fell apart."