Porn star introducing Wild At Heart in a threatening manner (8)
I believe the answer is:
stormily
'in a threatening manner' is the definition.
I can't judge whether this definition defines the answer.
'porn star introducing wild at heart' is the wordplay.
'porn star' becomes 'stormy' (I can't justify this - if you can you should believe this answer much more).
'introducing' indicates putting letters inside (some letters introduced or inserted into others).
'at heart' means to look at the middle letters.
The middle letters of 'wild' are 'il'.
'stormy' going around 'il' is 'STORMILY'.
Can you help me to learn more?
(Other definitions for stormily that I've seen before include "considerable violence" , "In a violent manner" .)