what is a lingam?
According to Monier Williams and Yudit Greenberg, "linga" means 'mark, sign or emblem',Wendy Doniger, view "linga" merely as an erotic phallic symbol,Moriz Winternitz, the "linga" is "only a symbol of the productive and creative principle of nature.
Shiva
 According to Monier Williams and Yudit Greenberg, "linga" literally means 'mark, sign or emblem', and also refers to a "mark or sign from which the existence of something else can be reliably inferred". It implies the regenerative divine energy innate in nature, symbolized by Shiva. Some scholars, such as Wendy Doniger, view "linga" merely as an erotic phallic symbol, although this interpretation is criticized by others, including Swami Vivekananda, Sivananda Saraswati, and S. N. Balagangadhara. According to Moriz Winternitz, the "linga" in the Shiva tradition is "only a symbol of the productive and creative principle of nature as embodied in Shiva", 
what is the name of the hindu liberator god Vishnu who did he liberate? UNANSWERABLE from what? UNANSWERABLE by what other names is he known? Hari , Kala, Vasudev, Purusa, Atman and Prakrti who is shiva? One of the principal deities of Hinduism which traditions are associated with him? Smarta tradition in which forms does he appear? Nataraja, Nityanarta, Dakshinamurthy,Ardhanarishvara how is he depicted? Nataraja (Sanskrit: ', "Lord of Dance") why was he called the destroyer? Because he is one of the supreme beings who creates, protects and transforms the universe and who referred to him as their benefactor? Hindus. which are the types of iconographic forms of him? Nataraja, Nityanarta, Dakshinamurthy,Ardhanarishvara
wiki:19655649
Shiva [SEP] Lingam
In that hymn, a description is found of the beginningless and endless "Stambha" or "Skambha", and it is shown that the said "Skambha" is put in place of the eternal Brahman. Just as the Yajna (sacrificial) fire, its smoke, ashes, and flames, the "Soma" plant, and the ox that used to carry on its back the wood for the Vedic sacrifice gave place to the conceptions of the brightness of Shiva's body, his tawny matted hair, his blue throat, and the riding on the bull of the Shiva, the "Yupa-Skambha" gave place in time to the "Shiva-Linga". In the text "Linga Purana", the same hymn is expanded in the shape of stories, meant to establish the glory of the great Stambha and the superiority of Shiva as Mahadeva.