MICHTAM. KJV and ASV form of Miktam.
MIKTAM mĭk’ təm (מִכְתָּ֥ם). The heading of Psalms 16, 56-60, and prob. of the hymn in Isaiah 38:9. It prob. has to do with the expiation of sin, but this is uncertain. KJV has MICHTAM.
International Standard Bible Encyclopedia (1915)