tierce vs digit

tierce and digit both are nouns.

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

As nouns, digit is a hypernym of tierce; that is, digit is a word with a broader meaning than tierce:

Other hypernyms of tierce include figure.

tierce (noun)	digit (noun)
one of three equal parts of a divisible whole	a finger or toe in human beings or corresponding body part in other vertebrates
the cardinal number that is the sum of one and one and one	one of the elements that collectively form a system of numeration
the third canonical hour; about 9 a.m.	the length of breadth of a finger used as a linear measure