Being misleading, the ad one really disliked (5)
I believe the answer is:
hated
'disliked' is the definition.
(hating is a kind of disliking)
'being misleading the ad' is the wordplay.
'being misleading' indicates anagramming the letters (I've seen this in other clues).
'the'+'ad'='thead'
'thead' anagrammed gives 'HATED'.
'one really' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for hated that I've seen before include "Heartily disliked" , "Abhorred" , "gave stinking review to?" , "Unpopular" , "viewed with hostility" .)