margin of error vs margin of safety

margin of error and margin of safety both are nouns.

Word	Noun	Adjective	Verb	Adverb
margin of error	Yes	No	No	No
margin of safety	Yes	No	No	No

As nouns, margin of error and margin of safety are synonyms defined as:

margin of error and margin of safety: the margin required in order to insure safety

Other synonyms of margin of error include safety margin.

margin of error (noun)	margin of safety (noun)
the margin required in order to insure safety	the margin required in order to insure safety