Old English hladan (past tense hlod, past participle gehladen) "to load, heap up, burden" (the general Germanic sense), also "to draw or take up water" (a meaning peculiar to English), from Proto-Germanic *hlathan- (source also of Old Norse hlaða "to pile up, load, especially a ship," Old Saxon hladan, Middle Dutch and Dutch laden, Old Frisian hlada "to load," Old High German hladen, German laden), from PIE *klā- "to spread out flat" (source also of Lithuanian kloti "to spread," Old Church Slavonic klado "to set, place").
In modern use restricted to the loading of ships; past participle laden was active in the language longer, but in 20c. was displaced by loaded (but a distinct word in the literal sense would be useful) except in particular phrases. Compare Lading.
<a href="https://www.etymonline.com/word/laden">Etymology of laden by etymonline</a>
Harper, D. (n.d.). Etymology of laden. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/laden