Meaning of Shiv ling based on Vedic sources and commentary of Vedic sages such as Swami Vivekanand, Swami Sivanand and Shri Ram Sharma Acharya of Gayatri Parivar(Haridwar).
‘Linga’ in Sankrit means form or mark and it is shaped like an egg and represents the ‘Brahmanda’ or the cosmic egg. Thus it represents elliptical form of divinity.
A glance at the image of Shiva Lingam shows there is a pillar with three marks and a disc beneath it called ‘Peetham’ and with a coiling cobra snake around the Pillar and shows its fangs above the pillar.
Shiva Lingam represents the totality of the Cosmos and the Cosmos, in turn, being represented as a Cosmic Egg. Again an egg is an ellipsoid depicting with no beginning, nor end.
Shiva being worshipped as Linga means the Consciousness in its primodal form where consciousness is entering into the Eternal Energy (Shakti).
Base of the ligna is called ‘Peetham’ and Coiled Cobra snake represents the ‘Kundalini’ shakti or feminine principle of the divinity whom we refer as Mother goddess. Three rows on pillar represents ‘Brahma’, Vishnu and Mahesh – different aspects of the divinity.
When un-manifest energy begins to manifest itself, the first form is always the Linga. The word Linga means the form. Why we are referring to it as the form is: the first form in the existence is always a Linga. Linga means a perfect ellipsoid.
The first form of creation is an ellipsoid and final form before dissolution is also an ellipsoid.Thus the first form is a Linga and the final form before dissolution is also a Linga. If you become meditative, your energies will naturally take the form of a Linga.
Thus Linga means Linga means the place of dissolution for the world and all beings. It signifies also Satya, Jnana and Ananta—Truth, knowledge and Infinity. It indicates that Lord Siva is endowed with all-pervading and self-luminous nature. Linga is a symbol which makes us understand the various kinds of Artha which are indicated above.
There are six Lingas, viz., Anda Linga, Pinda Linga, Sadasiva Linga, Atma Linga, Jnana Linga and Siva Linga. These Lingas are taken to mean the characteristics by which the Anda (the Universe), Pinda (the body), Sadasiva, etc., are to be recognized and understood.
Linga is only the outward symbol of the formless being, Lord Siva, who is the indivisible, all-pervading, eternal, auspicious, ever-pure, immortal essence of this vast universe, who is the undying Soul seated in the chambers of your heart, who is your In-dweller, innermost Self or Atman, and who is identical with the Supreme Brahman.