hanger-on vs tagalong

hanger-on and tagalong both are nouns.

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

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

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

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