Justifiable

google

ref

early 16th century (in the sense ‘justiciable’): from French, from justifier ‘to justify’.

wiktionary

ref

From Middle French justifiable

etymonline

ref

justifiable (adj.)

"capable of being proved just or true, morally defensible," 1520s, from Old French justifiable, from justifiier (see justify). Earlier in same sense was justificable (mid-15c.). Related: Justifiably (mid-15c.).