live load vs burden

live load and burden both are nouns.

Word	Noun	Adjective	Verb	Adverb
live load	Yes	No	No	No
burden	Yes	No	Yes	No

As nouns, burden is a hypernym of live load; that is, burden is a word with a broader meaning than live load:

live load: a variable load on a structure (e.g. a bridge) such as moving traffic
burden: weight to be borne or conveyed

Other hypernyms of live load include load, loading.

live load (noun)	burden (noun)
a variable load on a structure (e.g. a bridge) such as moving traffic	weight to be borne or conveyed
	the central idea that is expanded in a document or discourse
	an onerous or difficult concern
	the central meaning or theme of a speech or literary work

live load (verb)	burden (verb)
	impose a task upon, assign a responsibility to
	weight down with a load