Shomer

also called Shimrith · A Moabite, in the time of the Divided Monarchy · Moab · named in 2 verses

the name means keeper Strong's Lexicon

Shomer (or Shimrith) was a Moabite woman, the mother of Jozabad (or Zabad), who was one of the assassins of King Joash of Judah.

From Easton's Bible Dictionary

Watchman. (1.) The mother of Jehozabad, who murdered Joash (2 Kings 12:21); called also Shimrith, a Moabitess (2 Chr. 24:26).

Easton's Illustrated Bible Dictionary, 1897 — public domain, quoted in full and unedited.

From STEPBible's TIPNR genealogy data. A relationship the data marks uncertain is not shown here.

First named at 2 Kings 12:21.

2 Kings 12:21 His servants Jozabad son of Shimeath and Jehozabad son of Shomer struck him down, and he died. And they buried him with his fathers in the City of David, and his son Amaziah reigned in his place.
2 Chronicles 24:26 Those who conspired against Joash were Zabad son of Shimeath the Ammonitess and Jehozabad son of Shimrith the Moabitess.