Yes, overboard is a compound word.
Your word in Jettison
stop being lazy and do it yourself but here is a sentence they throw the boxes overboard
Oatmeal, offhand, offshoot, online, otherwise, outdoor, outfield, outfit, outgrow, outlaw, outlet, outlook, outnumber, outpatient, outside, overboard, overcoat, overdose, overdue and overuse are compound words. They begin with the letter o.
disembark
No, building is not a compound word.
Jettison.
The contraction (not a compound word) is doesn't.
Upwards is a compound word.
There is no compound word.A compound word is a word like bus-stop.Husban is spelt like this husband
Upstairs is a compound word, so it is one word.
The word that means that is jetsam The word that means that is jetsam
This word does not exist i think your thinking about the word jettison which is to throw something overboard or to discard