deep-six vs throw overboard

deep-six and throw overboard both are verbs.

Word	Noun	Adjective	Verb	Adverb
deep-six	No	No	Yes	No
throw overboard	No	No	Yes	No

As verbs, deep-six and throw overboard are synonyms defined as:

deep-six (verb)	throw overboard (verb)
throw from a boat	throw from a boat
toss out; get rid of	lose (something) or lose the right to (something) by some error, offense, or crime