出典:Wiktionary
From finite + -itude, or from Renaissance Latin finitūdō (“signifying a noun of state”).
finitude (countable かつ uncountable, 複数形 finitudes)
Finitude is rather formal and used in philosophy, while finiteness is used in mathematics; however, infinitude is used in mathematics more than infiniteness. Less formal is to reword to use limited: “(the fact that) life is limited” rather than “the finitude of life”.