PIE base ‘to be aware, make aware’. See also PIE base *weg-, root of awake.

Other derivatives include bid, from Old English bēodan, forbid, beadle, from Old English bydel ‘a person who makes a proclamation’,  ombudsman ‘official appointed to investigate complaints by individuals against institutions or authorities’, from Old Norse bodh ‘command’

Also Sanskrit budh ‘to wake up, be awake’, root of buddhi ‘intelligence, discernment, the power of forming and retaining conceptions and general notions’. So buddha means ‘awakened, awake’, giving the title of Buddha ‘awakened one’ to Siddhartha Gautama, also known as Shakyamuni, ‘Sage of the Shakya clan’.

[Pokorny bheudh- ‘to be awake, aware’, pp. 150–152.]