means A reason or explanation offered to show that an action, belief, or claim is right, reasonable, or warranted.

from From Latin 'justificare,' to make just or righteous — a fusion of 'justus' (just, lawful) and 'facere' (to make, do). It entered English through Old French in the medieval period, carrying a heavy theological charge: to be 'justified' was to be made righteous before God. Only later did the word loosen into the everyday sense of merely making a case for oneself — a slide from divine vindication to the excuses we offer at dinner.