michtam a technical term found in psalm titles meaning uncertain
Full Brown-Driver-Briggs lexicon entry
מִכְתָּםnoun [masculine]Mikhtam, a technical term in Psalm titles, meaning unknown (ᵐ5στηλογθαφια: compare BaePs. p. xiii f.); always with לְדָוִד֯׃לְדָוִד׳מPs 16:1; Ps 60:1׳לְדָוִד מPs 56:1; Ps 57:1; Ps 58:1; Ps 59:1.