digit vs finger's breadth

digit and finger's breadth both are nouns.

Word	Noun	Adjective	Verb	Adverb
digit	Yes	No	No	No
finger's breadth	Yes	No	No	No

As nouns, digit and finger's breadth are synonyms defined as:

digit and finger's breadth: the length of breadth of a finger used as a linear measure

Other synonyms of digit include finger, fingerbreadth.

digit (noun)	finger's breadth (noun)
a finger or toe in human beings or corresponding body part in other vertebrates	the length of breadth of a finger used as a linear measure
one of the elements that collectively form a system of numeration
the length of breadth of a finger used as a linear measure