punchball vs punching ball

punchball and punching ball both are nouns.

Word	Noun	Adjective	Verb	Adverb
punchball	Yes	No	No	No
punching ball	Yes	No	No	No

As nouns, punchball and punching ball are synonyms defined as:

punchball and punching ball: an inflated ball or bag that is suspended and punched for training in boxing

Other synonyms of punchball include punch bag, punching bag.

punchball (noun)	punching ball (noun)
an inflated ball or bag that is suspended and punched for training in boxing	an inflated ball or bag that is suspended and punched for training in boxing