Kantha means neck or throat. Bholenath, whose neck is shining with the effulgence of his opulence, is named as Shrikanth. Lord Shankar’s neck is the abode of all riches. For the benefit of his devotees, there is falling an incessant rain of material comforts from throat of Shrikanth. Till today Lord Kaamaari (Enemy of Kamdeva, deity of lust) is never reluctant to grant anything to anyone. Sometimes he gave out the things which were not worthy to give, and thus he got trapped in his own charities. Lord Aughardani alone may impart supreme knowledge to renounced and material enjoyments to worldly people.

At the time of churning the ocean there appeared the most terrible poison called Halahal. But the question was that who will bear it. Just by the flames of that poison, Lord Vishnu got black and he was named as Shyam-sundar. Lord Vamdeva was present there with his consort Parvati, and he was sweetly smiling. Suddenly Vishnu thought out—“oh! It is possible for Mahadeva only to drink this poison. No one else could do this. If we waste the time in discussion, then this powerful poison will devour the entire creation. So let us proceed towards Lord Shankar.” Lord Vishnu requested to Pinaki that O Lord! Please protect the three worlds and restrain this frightening poison. Hearing this, though noble Parvati’s serious looks were an indication of prohibition, but Vishnu’s appeal was on the other side. Lord Shambhu is omnipotent, so he honored both of them. He drank the poison and never drank as well. He stored that blue colored poisonous liquid inside his throat, and thus Shrikanth became Neel-Kanth for ever. When Shiva was drinking poison in order to prevent the mass-destruction, then Brahma ji started singing his glories— O Lord! This blue color is enhancing the beauty of your neck. Please remain like this perpetually. Then Bhasma-Dhari stored the poison there itself and got the title of Shrikanth.

Actually if poison was left outside, that could cause total annihilation. And if it could reach inside then all creatures would have died, because his abdomen is abode of all living beings. Therefore Umapati stopped it in the middle. A detailed narration of this story is found in Vayu-Purana which is incredible —

ततोऽहं पातुमारब्धो विषमन्तकसन्निभम्।
पिबतो मे महाघोरं विषं सुरभयंकरम्॥
कण्ठः समभवत्तूर्णं कृष्णो मे वरवर्णिनि।
तं दृष्ट्वोत्पलपत्राभं कण्ठे सक्तमिवोरगम्॥
अथोवाच महातेजा ब्रह्मा लोकपितामहः।
शोभसे त्वं महादेव कण्ठेनानेन सुव्रत्॥
ततस्तस्य वचः श्रुत्वा मया गिरिवरात्मजे।
पश्यतां देवसंघानां दैत्यानां च वरानने॥
यक्षगंधर्वभूतानां पिशाचोरगरक्षसाम्।
धृतं कण्ठे विषं घोरं नीलकण्ठस्ततो ह्यहम्॥

Even the toughest poison may not react adverse to Vrishabh-Vahan ( One who is riding on a bull) because he is already free from poison of sensual pleasures. So that became an ornament of powerful Lord and Lord Shankar became more ideal for all.

In the Anushasan-Parva Chapter of great epic Mahabharata, the name Shrikanth is interpreted differently. Being intoxicated by his opulence, Indra attacked on Lord Shiva by his fierce thunderbolt weapon. That weapon stroke straight at the neck, turning that part bluish. Consequently Lord Shiva is named as Neelkanth.

इन्द्रेण च पुरा वज्रं क्षिप्तं श्रीकांक्षिणा मम।
दग्ध्वा कण्ठं तु तद्यातं तेन श्रीकण्ठता मम॥

According to Nana-Artha-Ratnamala, word ‘Shri’ can also be translated as poison. So Vishnu-Vallabh is titled as Shrikanth for holding poison in his throat. As per definitions found in Aalwal—

क्ष्वेलं गंगामिन्दोर्लेखामाद्योत्थां या कान्तिं कंठे।
बिभ्रन्माण्डल्येशे लिंगे विख्यातोऽसि त्वं श्रीकंठः॥

O Lord! You are called Shrikanth for sustaining three things namely poison, Ganges and moon. Where ‘Shri’ ‘kam’ and ‘tha’; these three things are present, that is called ‘Shrikanth’. ‘Shri’ means poison, ‘kam’ means Ganges and ‘tha’ means moon. Shankar is known as Shrikanth for holding these three things together.

Our Gurudev says that Shrikanth is actually the ignorance based secondary form of Absolute Brahman. Though impersonal, he shows his personal form to his devotees. This proves the loving nature of the Lord that he does even impossible for his devotees. Therefore one must become a devotee of Bharg. Lord Shrikanth is the master of all opulence and one should ask even the mundane things from him only, this is the true form of worship of Shrikanth.