Semicha ("leaning [of the hands]"), also "semichut" ("ordination"), or "semicha lerabbanut" ("rabbinical ordination") is derived from a Hebrew word which means to "rely on" or "to be authorized". It generally refers to the ordination of a rabbi within Judaism. In this sense it is the "transmission" of rabbinic authority to give advice or judgment in Jewish law. Wikipedia
The definitive Wikipedia entry for Semicha. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Semicha