Irritated by some journalist penning denial (7)
I believe the answer is:
annoyed
'irritated' is the definition.
(synonyms)
'some journalist penning denial' is the wordplay.
'some' becomes 'any' (similar in meaning).
'journalist' becomes 'ed' (short for editor).
'penning' is an insertion indicator.
'denial' becomes 'no' (no is a kind of denial).
'any'+'ed'='anyed'
'anyed' going around 'no' is 'ANNOYED'.
'by' acts as a link.
(Other definitions for annoyed that I've seen before include "put out" , "Displeased" , "'Harassed, pestered (7)'" , "Anodyne (anag.)" , "Irritated, irked" .)