The most common and most likely answer to this crossword clue is the 8 letter word PEMBROKE
I've seen this crossword clue in The Guardian
P
E
M
B
R
O
K
E
More clues leading to the result PEMBROKE
- Under pressure, European married, penniless, in Welsh town
- Quiet English male lacking funds in Welsh town
- Gym miles to the west of ruined Welsh castle
- Finally free in afternoon, what gamblers go for in Welsh town
- Politician turned up penniless in Welsh town
- Dashed after Euro-politician’s returned for part of Wales
- Pressure to take measure against bankrupt Welsh market town
- European politician returning without money for college
- Welsh town where the leaves drop?
- Cameron admits English ruined Welsh port
Buddy explains!

The straight part
We know that "Welsh port" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case welsh port = pembroke.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.