laden vs load down

laden is an adjective but load down is not an adjective.

Word	Noun	Adjective	Verb	Adverb
laden	No	Yes	Yes	No
load down	No	No	Yes	No

As verbs, load down is a hyponym of laden; that is, load down is a word with a more specific, narrower meaning than laden:

Other hyponyms of laden include pack, bomb up, overcharge, overload, surcharge, reload, stack.

laden (adjective)	load down (adjective)
burdened psychologically or mentally
filled with a great quantity

laden (verb)	load down (verb)
remove with or as if with a ladle	load with a pack
fill or place a load on