Here’s how I understand it. It essentially means “holier.” In Catholic theology, justification and sanctification (holiness) are a united concept. The closer you get to your final heavenly state, the holier you can be said to be, or “more” justified. Paul talks about this in being “mature” in the faith, or in Hebrews we are told God chastises those who are
already His sons for the sake of their holiness, etc…
Church docs reflecting this idea can be found in the Catechism section on
Justification and Grace.
And from the
Council of Trent, session VI:*CHAPTER VII –
Justification itself, which is not remission of sins merely, but also the sanctification and renewal of the inward man, through the voluntary reception of the grace, and of the gifts, whereby man of unjust becomes just, and of an enemy a friend, that so he may be an heir according to hope of life everlasting.
…
CHAPTER X – Having, therefore, been thus justified, and made the friends and domestics of God, advancing from virtue to virtue, they are renewed, as the Apostle says, day by day; that is, by mortifying the members of their own flesh, and by presenting them as instruments of justice unto sanctification, they, through the observance of the commandments of God and of the Church, faith co-operating with good works,
increase in that justice which they have received through the grace of Christ, and are still further justified, as it is written; He that is just, let him be justified still; and again, Be not afraid to be justified even to death; and also, Do you see that by works a man is justified, and not by faith only. And this
increase of justification holy Church begs, when she prays, “Give unto us, O Lord, increase of faith, hope, and charity.”*
