No, I didn't make up another meaning for 'justify'.
From Vine's:
Vine's Expository Dictionary of New Testament Words
101 Verb Strong's Number:
g1344 Greek:
dikaioo
Justification, Justifier, Justify:
primarily, "to deem to be right," signifies, in the NT,
(
a) "
to show to be right or righteous;" in the Passive Voice, to be justified,
Mat 11:19;
Luk 7:35;
Rom 3:4;
1Ti 3:16;
(
b) "
to declare to be righteous, to pronounce righteous,"
https://www.blueletterbible.org/lang/lexicon/lexicon.cfm?Strongs=G1344&t=KJV
Here are two Biblical examples of justified meaning 'to
show to be right or righteous':
"...wisdom is justified of her children." - Matthew 11:19
"29 But he, willing to justify himself, said unto Jesus, And who is my neighbour?” - Luke 10:29
We know that James is using this definition of 'justified' in James 2:24 because if he was using the other definition of justified he'd be saying works make you righteous, which we all know is not Biblical at all:
"24 Ye see then how that by works a man is justified, and not by faith only." - James 2:24
The verse is only Biblically accurate if justified means 'to show one to be righteous'. Works justify you in that they show you to be righteous, not make you to be righteous, just as wisdom is shown to be right(eous) by what it bears, and how the Lawyer was trying to show himself to be righteous by what he said, not make himself righteous by what he said (that doesn't even make sense).