The word Shivalingam has been derived from sanskrit roots Shiva (Lord) + Lingam (Mark/Chinha/Symbol). Hence, Shivalingam is the mark of lord within its creation. Everything in the world arises out of a dome/a ball/ a pindi……be it a tree which comes from a seed which is round, a child which comes from a cell which is round, all heavenly bodies are round, the minutest of cells are round and our very earth is round. Every thing being round is a mark of the Lord/Shiva. Since Shiva cant be comprehended, we worship his mark or we worshib the whole Brahmman in a Shivalingam. Philosophically, Shiva Lingam consists of three parts. The bottom part which is four-sided remains underground, the middle part which is eight-sided remains on a pedestal. The top part, which is actually worshipped, is round. The height of the round part is one-third of its circumference. The three parts symbolize Brahma at the bottom, Vishnu in the middle and Shiva on the top. The pedestal is provided with a passage for draining away the water that is poured on the top. The Lingam symbolizes both the creative and destructive power of Lord Shiva and great sanctity is attached to it by the devotees. This does not mean others should give a false meaning to the image of Shiva Lingam.
It is unfortunate for some critics to have an imaginary invention on the image of Shiva Lingam as a male organ and viewed with obscenity, but had conveniently forgotten how a phallus could have appeared from the base. Moreover, since Lord Shiva is described as having no form, it is ridiculous to maintain that Lingam represents a phallus. This is the reason why Swami Vivekananda described Shiva Lingam as the symbol of the Eternal Brahman, when a German Orientalist, Gusta Oppert traced it to phallicism. Swami Vivekanand cited Atharva Veda that the worship of Shiva Lingam was sung in praise of sacrificial post – a description of the beginning less and endless of the Eternal Brahman and refuted it as an imaginary invention.