pin down vs determine

pin down and determine both are verbs.

Word	Noun	Adjective	Verb	Adverb
pin down	No	No	Yes	No
determine	No	No	Yes	No

As verbs, determine is a hypernym of pin down; that is, determine is a word with a broader meaning than pin down:

pin down (verb)	determine (verb)
define clearly	reach, make, or come to a decision about something
attach with or as if with a pin	fix conclusively or authoritatively
place in a confining or embarrassing position	shape or influence; give direction to
	fix in scope; fix the boundaries of
	establish after a calculation, investigation, experiment, survey, or study
	find out, learn, or determine with certainty, usually by making an inquiry or other effort
	decide upon or fix definitely
	settle conclusively; come to terms