V. S. Apte, The Practical Sanskrit–English Dictionary. Look up any word of the Gita in Devanagari, IAST or Harvard-Kyoto, or browse the headwords letter by letter.
Entry स्वरु
स्वरुsvaruSunshine.
[स्वृ-उ]
Sunshine.
A part of a sacrificial post.
A sacrifice.
A thunderbolt; स्वरुणा विहतं सद्यो गिरेः शृङ्गमिवापतत् Śiva B.21.51.