set down vs touch down

set down and touch down both are verbs.

Word	Noun	Adjective	Verb	Adverb
set down	No	No	Yes	No
touch down	No	No	Yes	No

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

set down (verb)	touch down (verb)
put down in writing; of texts, musical compositions, etc.	come or bring (a plane) to a landing
remove (cargo, people, etc.) from and leave
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