The most common and most likely answer to this crossword clue is the 6 letter word ODESSA
I've seen this crossword clue in Financial Times
O
D
E
S
S
A
More clues leading to the result ODESSA
- Ukrainian port where poetic works have a certain appeal
- Poems by Tasso regularly turning up in Ukrainian port
- Unlimited load of French ship entering Black Sea Port
- Port passed, offering bottles to the left
- Rough seas do for Black Sea port
- Some abodes sailors selected in port
- Poetry on South African port
- Died having been flayed over in seaport
- Administered doses before a port
- Horatian work as retrospective in seaport
Buddy explains!

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