to show (an act, claim, statement, etc.) to be just or right

The end does not always justify the means.

to defend or uphold as warranted or well-grounded

Don't try to justify his rudeness.

Theology . to declare innocent or guiltless; absolve; acquit.

Printing .

to make (a line of type) a desired length by spacing the words and letters, esp. so that full lines in a column have even margins both on the left and on the right.

to level and square (a strike).

Law .

to show a satisfactory reason or excuse for something done.

to qualify as bail or surety.

Printing . (of a line of type) to fit exactly into a desired length.