burden vs overburden

burden and overburden both are nouns.

Word	Noun	Adjective	Verb	Adverb
burden	Yes	No	Yes	No
overburden	Yes	No	Yes	No

As nouns, overburden is a hyponym of burden; that is, overburden is a word with a more specific, narrower meaning than burden:

Other hyponyms of burden include burthen, dead load, live load, superload, millstone, overload, overload.

As verbs, overburden is a hyponym of burden; that is, overburden is a word with a more specific, narrower meaning than burden:

Other hyponyms of burden include bear down, deluge, flood out, overwhelm, adjure.

As verbs, overburden is a hyponym of burden; that is, overburden is a word with a more specific, narrower meaning than burden:

Other hyponyms of burden include plumb, saddle.

burden (noun)	overburden (noun)
weight to be borne or conveyed	an excessive burden
the central idea that is expanded in a document or discourse	the surface soil that must be moved away to get at coal seams and mineral deposits
an onerous or difficult concern
the central meaning or theme of a speech or literary work

burden (verb)	overburden (verb)
impose a task upon, assign a responsibility to	burden with too much work or responsibility
weight down with a load	load with excessive weight