burden vs overload

burden and overload both are nouns.

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

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

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

burden (noun)	overload (noun)
weight to be borne or conveyed	an excessive burden
the central idea that is expanded in a document or discourse	an electrical load that exceeds the available electrical power
an onerous or difficult concern
the central meaning or theme of a speech or literary work

burden (verb)	overload (verb)
impose a task upon, assign a responsibility to	fill to excess so that function is impaired
weight down with a load	place too much a load on
	become overloaded