Talking about the things of God never gets old. The most crucial dictionary definition for righteousness you cited is this:
1. Just; accordant to the divine law. Applied to persons, it denotes one who is holy in heart, and observant of the divine commands in practice; as a righteous man. Applied to things, it denotes consonant to the divine will or to justice; as a righteous act. It is used chiefly in theology, and applied to God, to his testimonies and to his saints. The righteous, in Scripture, denote the servants of God, the saints.
The reason I say that is because it fits in with the Bible's own definition in Psalm 119:172 "My tongue shall speak of Thy word: for all Thy commandments are righteousness."
This goes hand in glove with the Lord's own words in the Sermon on the Mount: "But seek ye first the kingdom of God and His righteousness; and all these things shall be added unto you."
Amen! Great verse you shared in Psalm 119! I personally believe that Psalm 119 is all about the RIGHTEOUS character and Person of Jesus Christ (and God Head) and His RIGHTEOUS attributes; experiencing them and enjoying them in an abiding relationship to Him (Gal. 2:20/1 Peter 1:7-9)! and Matt. 6:33 is crucial and key for a saving relationship to God and all He has for us!
God speed bro!