digit vs fingerbreadth

digit and fingerbreadth both are nouns.

Word	Noun	Adjective	Verb	Adverb
digit	Yes	No	No	No
fingerbreadth	Yes	No	No	No

As nouns, digit and fingerbreadth are synonyms defined as:

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

Other synonyms of digit include finger's breadth, finger.

digit (noun)	fingerbreadth (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