/ Dictionary / Index J jam session: Meaning and Definition of Find definitions for: jam' ses"sion Pronunciation: [key] a meeting of a group of musicians, esp. jazz musicians, to play for their own enjoyment. an impromptu jazz performance or special performance by jazz musicians who do not regularly play together. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. jams Jamshedpur Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language