Somewhat oral, might produce maths function (9)
I believe the answer is:
logarithm
'maths function' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'somewhat oral might' is the wordplay.
'oral might' anagrams to 'LOGARITHM'.
But, I'm not sure how this is indicated.
'produce' is the link.
Can you help me to learn more?
(Other definitions for logarithm that I've seen before include "Mathematical aid simplifying multiplication and division - a girl moth (anag)" , "Aid to mathematical calculation" , "Exponent" , "Power to which base number must be raised to obtain a given number" , "It undoes power" .)