Smicha in Jakarta, Indonesia

Smicha or semikhah also smichut, smicha lerabbanut, or smicha lehazzanut, is derived from a Hebrew word which means to "rely on" or "to be authorized".

Prevailing smicha generally refers to the ordination of a rabbi or cantor within post-talmudic Rabbinic Judaism, and within all modern Jewish religious movements from Reform to Orthodox. Smicha lerabbanut signifies the transmission of rabbinic authority to give advice or judgment in Jewish law. Smicha lehazzanut signifies the transmission of authoritative knowledge about Jewish musical and liturgical traditions. Although presently most functioning synagogue rabbis hold smicha lerabbanut by some rabbinical institution or academy, this was until quite recently not always required, and in fact many Haredi rabbis may not be required to hold a "formal" smicha lerabbanut even though they may occupy important rabbinical and leadership positions. Some cantorial institutions in the US currently grant smicha lehazzanut to their students, while others use the term "investiture" to describe the conferral of cantorial authority onto their graduates.