guidepost vs rule of thumb

guidepost and rule of thumb both are nouns.

Word	Noun	Adjective	Verb	Adverb
guidepost	Yes	No	No	No
rule of thumb	Yes	No	No	No

As nouns, guidepost and rule of thumb are synonyms defined as:

guidepost and rule of thumb: a rule or principle that provides guidance to appropriate behavior

Other synonyms of guidepost include guideline.

guidepost (noun)	rule of thumb (noun)
a rule or principle that provides guidance to appropriate behavior	a rule or principle that provides guidance to appropriate behavior
a post bearing a sign that gives directions or shows the way