In some scriptures Brahma is referred as Viranchi (विरञ्चि):
Whenever I see sun raising in early morning, following mantra automatically pops out from my mind/month:
नमः सवित्रे जगदेकचक्षुषे । जगत्प्रसूती स्थिति नाश हेतवे
त्रयीमयाय त्रिगुणात्म धारिणे । विरञ्चि नारायण शङ्करात्मने॥
Salutations to the Sun God, the Eye of the Universe, the Cause of Creation, Maintenance and Destruction of the Universe, the three Gunas, taking form as Brahma, Vishnu and Shiva.
Above mantra is from Surya Mandalashtaka.
Another example from memorized Narmadashtakam:
विरिञ्चि विष्णुशंकरस्वकीयधामवर्मदे त्वदीयपादपङ्कजं नमामि देवि नर्मदे ॥
The presence of Brahma, Vishnu and Shankara in Your Holy Dhama (i.e. River body) provides a Protective Shield (of Blessings to the Devotees), O Devi Narmada, I Bow down to Your Lotus Feet, Please give me Your Refuge.
As you've seen in above examples, Brahma is referred Viranchi (विरञ्चि). So, I want to know why is Brahma referred as Viranchi in Scriptures?