mal'ak (Hebrew #4397)
a messenger; specifically, of God, i.e. an angel (also a prophet, priest or teacher)
KJV usage: ambassador, angel, king, messenger.
Pronounce: mal-awk'
Origin: from an unused root meaning to despatch as a deputy
melek (Hebrew #4428)
a king
KJV usage: king, royal.
Pronounce: meh'-lek
Origin: from 4427