In the past I have covered the meaning of the word "Israel". During the reign of Solomon the one nation (body) of Israel was divided into the house of Israel and the house of Judah. YHVH prophetically knew the different natures and qualities of each house and recorded them for us in the writings of the prophets. House (beyt (בית)) is a place where a person belongs. It is a familial term. The house of Judah, inspite of their treachery and disobedience, would still preserve the Torah of our 'Elohiym.

Our Messiah comes from the house of Judah. However disobedient the house of Judah was, Yeshua‘ was the perfect model of the meaning of the name of this house. The word Judah is the Hebrew word yehudah. The root of this word is yadah (ידה), which means to lift the hand up in praise. Its first appearance, as is always the case, defines it's etymological meaning.

Bere’shiyt (Genesis) 29:35And she conceived again, and bare a son: and she said, Now will I praise YHVH: therefore she called his name Judah; and left bearing.

This a term used of true believers in the New Testament.

1 Kefa (1 Peter) 2:9But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:

When the fifth letter, hey (ה) of the Aleph-bet is inserted into the root of this word, then the meaning is "to become a yehudah". This can be accomplished by choice (as in Caleb in Bemidebar (Numbers) 13:6) or by deception (Eseter (Esther) 8:17, Hitgalut (Revelation) 3:9).

Shalom Alecheim!