thin out vs reduce

thin out and reduce both are verbs.

Word	Noun	Adjective	Verb	Adverb
thin out	No	No	Yes	No
reduce	No	No	Yes	No

As verbs, reduce is a hypernym of thin out; that is, reduce is a word with a broader meaning than thin out:

Other hypernyms of thin out include bring down, cut, cut back, cut down, trim, trim back, trim down.

As verbs, thin out and reduce are synonyms defined as:

thin out and reduce: lessen the strength or flavor of a solution or mixture

Other synonyms of thin out include cut, dilute, thin.

thin out (verb)	reduce (verb)
make sparse	take off weight
become sparser	cut down on; make a reduction in
lessen the strength or flavor of a solution or mixture	narrow or limit
	cook until very little liquid is left
	to remove oxygen from a compound, or cause to react with hydrogen or form a hydride, or to undergo an increase in the number of electrons
	make smaller
	reduce in size; reduce physically
	make less complex
	reduce in scope while retaining essential elements
	lessen the strength or flavor of a solution or mixture
	be cooked until very little liquid is left
	be the essential element
	destress and thus weaken a sound when pronouncing it
	undergo meiosis
	reposition (a broken bone after surgery) back to its normal site
	lower in grade or rank or force somebody into an undignified situation
	lessen and make more modest
	simplify the form of a mathematical equation of expression by substituting one term for another
	bring to humbler or weaker state or condition
	put down by force or intimidation