Achish

Achish - angry, perhaps only a general title of royalty applicable to the Philistine kings. (1.) The king with whom David sought refuge when he fled from Saul (1 Sam. 21:10-15). He is called Abimelech in the superscription of Ps. 34. It was probably this same king to whom David a second time repaired at the head of a band of 600 warriors, and who assigned him Ziklag, whence he carried on war against the surrounding tribes (1 Sam. 27:5-12). Achish had great confidence in the valour and fidelity of David (1 Sam. 28:1,2), but at the instigation of his courtiers did not permit him to go up to battle along with the Philistine hosts (1 Sam. 29:2-11). David remained with Achish a year and four months. (2.) Another king of Gath, probably grandson of the foregoing, to whom the two servants of Shimei fled. This led Shimei to go to Gath in pursuit of them, and the consequence was that Solomon put him to death (1 Kings 2:39-46).

From Easton's Bible Dictionary (1897)