Shiva Purana

siva.sh/siva-purana/saturda-samhita/2/7

बहिरंतर्जगद्विश्वं बिभर्ति स्पन्दतेस्य यम् ।। उग्र इत्युच्यते सद्भी रूपमुग्रस्य सत्प्रभो ।।७।।

sanskrit

The form of the great lord Śiva that holds the outer and inner universe and throbs by itself is called Ugra by the noble.

english translation

bahiraMtarjagadvizvaM bibharti spandatesya yam || ugra ityucyate sadbhI rUpamugrasya satprabho ||7||

hk transliteration by Sanscript