Definition:

: to indulge in the process or practice of thinking or telling about past experiences.

Examples: 

Justin met up with some of his college buddies to reminisce about old times.

“Most of us have a comfort food we eat when we are reminiscing, sad or depressed.” — Marion Goldberg, The Poughkeepsie (New York) Journal, 16 Dec. 2015

by MERRIAM-WEBSTER DICTIONARIES.