Definition of "nabla" [nabla]

• A Hebrew stringed instrument. (noun)
• The symbol ∇, used to denote the gradient operator. (noun)

Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License

• "I once wrote "nabla" (an Assyrian harp, term was introduced by the very Anglo Saxon Peter Tait) and I got a very antisemitic reaction to the extent that Jews want to turn everything into something Jewish, even math symbols."
• "The standard quantization is that momentum p is replaced with the operator (hbar/i) nabla (nabla is a directional derivative) and E = ihbar &/& t (& = partial)."
• "The real part is the instanton component that is a nabla S nabla I, reflecting the small quantum aspect of the spacetime — eg a WKB type of approximation."