Derived from the root ‘dīkṣ’ (‘to destroy ignorance by giving knowledge and wisdom’) the word dīkṣā has several meanings such as observing certain rules for a period of time, a rite to be performed at the beginning of a holy venture, like a Vedic sacrifice, the sacrament of upanayana, receiving a mantra (sacred formula) from a qualified guru and shaving the head as a part of a religious vow.
Dīkṣā is a must in all ritualistic acts.
Consecration of the sacrificer at the beginning of a Somayāga is also called ‘dīkṣā’. It takes place after some preliminaries like an iṣṭi and āhuti (offering a ladleful of ghee into the fire). The sacrificer has to wear a particular garment, a girdle of muñja grass and a piece of cloth as head-dress. He should also keep a daṇḍa as staff. His wife should wear a yoktra (a belt of muñja grass). They are expected to follow certain rules during the period of the sacrifice.
Imparting a mantra to a worthy disciple is called ‘dīkṣā’ in the tāntrik works. It is of several varieties. The guru can rouse the spiritual potential of the disciple by just a look or a touch. (See TANTRAS for details.)