Justification, n.
Etymology: [L. justificatio: cf. F. justification. See Justify.]
1. The act of justifying or the state of being justified; a showing or proving to be just or conformable to law, justice, right, or duty; defense; vindication; support; as, arguments in justification of the prisoner's conduct; his disobedience admits justification. I hope, for my brother's justification, he wrote this but as an essay or taste of my virtue. Shak.
2. (Law)
The showing in court of a sufficient lawful reason why a party charged or accused did that for which he is called to answer.
3. (Theol.)
3 more senses
The act of justifying, or the state of being justified, in respect to God's requirements. Who was delivered for our offenses, and was raised again for our justification. Rom. iv. 25. In such righteousness To them by faith imputed, they may find Justification toward God, and peace Of conscience. Milton.
4. (Print.)
Adjustment of type by spacing it so as to make it exactly fill a line, or of a cut so as to hold it in the right place; also, the leads, quads, etc., used for making such adjustment.
Shades of meaning
Fernald has no entry of its own for justification; he lists it under apology, defense.
Where he writes about it:
Defense, exculpation, justification, and vindication are more properly antonyms than synonyms of apology in its modern sense, and should be so given, but for their connection with its historic usage. — from apology