Wrongly tell head of marketing one's performing well (9)
I believe the answer is:
misinform
'wrongly tell' is the definition.
I can't tell whether this defines the answer.
'head of marketing one's performing well' is the wordplay.
'head of' says to take the initial letters.
'one's' becomes 'i's' (Roman numeral).
'performing well' becomes 'in form'.
The initial letter of 'marketing' is 'm'.
'm'+'is'+'inform'='MISINFORM'
Can you help me to learn more?
(Other definitions for misinform that I've seen before include "Give inaccurate info to (someone)" , "Fool" , "teach badly" , "Wrongly advise" , "Tell incorrectly" .)