tagalong vs hanger-on

tagalong and hanger-on both are nouns.

Word	Noun	Adjective	Verb	Adverb
tagalong	Yes	No	No	No
hanger-on	Yes	No	No	No

As nouns, tagalong and hanger-on are synonyms defined as:

tagalong and hanger-on: someone who persistently (and annoyingly) follows along

tagalong (noun)	hanger-on (noun)
someone who persistently (and annoyingly) follows along	someone who persistently (and annoyingly) follows along