The name Haggith in the Bible
There's one Haggith in the Bible and she isn't very fortunate. She is one of Israel's king David"s lesser known wives (2 Samuel 3:4) and her son is called Adonijah. Adonijah, very pretty but not very clever, plots against his elderly father for the kingdom, while this was promised and subsequently given to Solomon (1 Kings 1:5, 43).
Adonijah gets fiercely scared but is mercifully pardoned by Solomon. But when Adonijah has his mother Haggith ask Solomon's mother Bathsheba for the hand of the beautiful Abishag, the "nurse" of the deceased king David, he's really done it, and Solomon has him assassinated by Benaiah the son of Jehoiada (2:25).
Etymology of the name Haggith
The name Haggith comes from the verb חגג (hagag), meaning to celebrate, hold a feast:
For the meaning of this name Jones' Dictionary of Old Testament Proper Names reads Exultation but points at the name Haggai, which is the masculine version of this name, and which he translates with Festival Of The Lord. BDB Theological Dictionary and NOBSE Study Bible Name List both read Festal.