TITLE: How do we pronounce this symbol: $\nabla \phi$
QUESTION [5 upvotes]: I would like to know how to pronounce in English this symbol: $\nabla \phi$.
It is something phi  ... ?

REPLY [2 votes]: it's actually del operator, https://en.wikipedia.org/wiki/Del
so it is del phi, in mathematics.
nabla article points to that for mathematical usage https://en.wikipedia.org/wiki/Nabla_symbol