The most common and most likely answer to this crossword clue is the 5 letter word MARIA
I've seen this crossword clue in The Times
M
A
R
I
A
More clues leading to the result MARIA
- Woman mother has to show round
- Yacht haven keeping out November seas
- Maybe miss show in the morning, on getting up
- Some backing from fair American girl
- Lady starts to move about restlessly inside aeroplane
- A Winter’s Tale character with perfect stuff about
- Start of melodious song, song from West Side Story
- Mark has song for girl
- Musical’s lead song — this one?
- Revolutionary American character comes back with girl
Buddy explains!

The straight part
We know that "seas" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seas = maria.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.
What does MARIA mean?
MARIA noun- A large, dark plain, which may have the appearance of a sea.
- On Saturn's moon Titan, a large expanse of what is thought to be liquid hydrocarbons.