The most common and most likely answer to this crossword clue is the 3 plus 2 plus 3 letter word MAL DE MER
I've seen this crossword clue in The Times
M
A
L
D
E
M
E
R
More clues leading to the result MAL DE MER
- Being sick on ferry – just off Calais ?
- Whisky, mostly deficient cure for returning type of sickness
- Jean-Paul Sartre's deep discomfort?
- Feeling unwell on cruise? Remedial treatment includes meclizine at first, but without iodine.
- What’s upset me twice — lard, bringing a sort of sickness
- Upset on sea, wretched mostly — so it is!
Buddy explains!
The straight part
We know that "Being sick on ferry – just off Calais ?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case being sick on ferry – just off calais ? = mal de mer.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.