To jam is defined as to shove in so something gets stuck, to squeeze into a tight space, or is a causal term for playing music.(verb)
Jam is defined as being in an intense or difficult situation, or is a preserve made from whole fruit and sugar.(noun)
See jam in Webster's New World College Dictionary
Origin: < ?
Origin: < ? jam
See jam in American Heritage Dictionary 4
verb jammed jammed, jam·ming, jams verb, transitive
Origin: Origin unknown.
Origin: Possibly from jam1.
Learn more about jam