The most common and most likely answer to this crossword clue is the 4 letter word OBAN
I've seen this crossword clue in The Guardian
O
B
A
N
More clues leading to the result OBAN
- Graduate taken in about small Scottish port
- Old outlaw in Scottish town
- Scottish resort to herb tea infusion, last of all
- Beginning of big article on old Scottish resort town
- About to welcome group flying in port
- Find whisky here round bar
- Old boy and knight drinking a port
- Retired tycoon last to leave northern port
- 15 22 across ends up in Latin America, superb archipelago
- Scottish town where anything goes?
Buddy explains!

The straight part
We know that "port" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case port = oban.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.