Most stylish butt seen in Italian port, briefly (9)
I believe the answer is:
trendiest
'most stylish butt seen in italian port briefly' is the definition.
I can't judge whether this definition defines the answer.
'stylish butt seen in italian port briefly' is the wordplay.
'stylish butt' becomes 'end' (eg the butt or end of a cigarette. I am not sure about the 'stylish' bit.).
'seen in' indicates putting letters inside.
'italian port' becomes 'trieste' (I've seen this before).
'briefly' means to remove the last letter.
'trieste' with its last letter taken away is 'triest'.
'end' going inside 'triest' is 'TRENDIEST'.
Can you help me to learn more?
(Other definitions for trendiest that I've seen before include "Most popular" , "cooler than the rest" , "Most cool!" .)