set down vs dash off

set down and dash off both are verbs.

Word	Noun	Adjective	Verb	Adverb
set down	No	No	Yes	No
dash off	No	No	Yes	No

As verbs, dash off is a hyponym of set down; that is, dash off is a word with a more specific, narrower meaning than set down:

Other hyponyms of set down include transcribe, notate, dash down, note, take down.

set down (verb)	dash off (verb)
put down in writing; of texts, musical compositions, etc.	write down hastily
remove (cargo, people, etc.) from and leave	write quickly
put or settle into a position
cause to sit or seat or be in a settled position or place
go ashore
reach or come to rest