The Collaborative International Dictionary
Excusableness
Excusable \Ex*cus"a*ble\a. [L. excusabilis: cf. F. excusable. See Excuse.] That may be excused, forgiven, justified, or acquitted of blame; pardonable; as, the man is excusable; an excusable action. -- Ex*cus"a*ble*ness, n. -- Ex*cus"a*bly, adv.
The excusableness of my dissatisfaction.
--Boyle.
Wiktionary
excusableness
n. The quality of being excusable.