Awkward question about a set of mathematical processes (9)
I believe the answer is:
equations
'set of mathematical processes' is the definition.
(equations are mathematical processes)
'awkward question about a' is the wordplay.
'awkward' indicates anagramming the letters.
'about' is an insertion indicator.
'question' with letters rearranged gives 'equtions'.
'equtions' enclosing 'a' is 'EQUATIONS'.
(Other definitions for equations that I've seen before include "Mathematical assertions that two expressions are equal" , "'In maths, assertions that two expressions are equal (9)'" .)