The most common and most likely answer to this crossword clue is the 5 letter word RABAT
R
A
B
A
T
More clues leading to the result RABAT
- Sailor trapped by traitor in an Atlantic port
- After putting up reserve, save capital
- Republican launching a club in African capital
- Rwandan leader a hit in African capital
- Capital, that of Russia, a hit
- Jacket turned up and shortened? Capital
- Short tunic from the bottom part of Morocco
- Scot meets a model in African capital
- Venue for pilgrims mostly returning to rotate in a way
- Capital given stick by artist
Buddy explains!

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