jam vs crowd together

jam is a noun but crowd together is not a noun.

Word	Noun	Adjective	Verb	Adverb
jam	Yes	No	Yes	No
crowd together	No	No	Yes	No

As verbs, crowd together is a hypernym of jam; that is, crowd together is a word with a broader meaning than jam:

Other hypernyms of jam include crowd.

jam (noun)	crowd together (noun)
deliberate radiation or reflection of electromagnetic energy for the purpose of disrupting enemy use of electronic devices or systems
preserve of crushed fruit
a dense crowd of people
informal terms for a difficult situation

jam (verb)	crowd together (verb)
interfere with or prevent the reception of signals	to gather together in large numbers
crowd or pack to capacity
get stuck and immobilized
block passage through
crush or bruise
press tightly together or cram
push down forcibly