The other day the word onderwerp [ˈɔndərwɛrp] came up in one of my Dutch lessons. It means subject, topic or issue, and to help me remember it, I decided to look into its etymology.
It comes from onder (under, among) and werpen (to throw, shed, cast), and is a calque of the Latin word subiectum (that which is spoken of, the foundation or subject of a proposition) [source].
Related expressions include onderwerpen (to subject), onderwerping (submission, subjugation, subjection), onderwerpszin (subject clause), gespreksonderwerp (topic of conversation, talk, conversation piece), nieuwsonderwerp (news item)
Subiectum comes from subiciō (throw under or near; supply; forge; subject; propose), from sub- (under) and iaciō (throw, hurl). The English word subject comes from the same root, as do related words in other languages, such as sujet (subject, cause, reason) in French, and soggetto (subject, dependent) in Italian [source].
So an onderwerp and a subject is something that is thrown under.
A related Dutch word is voorwerp [ˈvoːrˌʋɛrp], which means object or item, and comes from voor (for, before, in front of) and werpen (to throw, shed, cast), and is a calque of the Latin word obiectum (a charge, accusation), which is the root of object comes from the same root, as do related words in other languages, from obiciō (throw to; offer, present) [source]