The most common and most likely answer to this crossword clue is the 5 letter word SALTY
I've seen this crossword clue in The Guardian
S
A
L
T
Y
Buddy explains!
The straight part
We know that "Seasoned" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seasoned = salty.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 SALTY mean?
SALTY adjective- Tasting of salt.
- Containing salt.
- Coarse, provocative, earthy; said of language.
- Experienced, especially used to indicate a veteran of the naval services; salty dog (from salt of the sea).
- Irritated, annoyed (from the sharp, spicy flavor of salt).
- Indignant or offended due to over-sensitivity, humourlessness, disappointment, or defeat (implying the person is a crybaby, shedding salty tears); said of interlocutors expressing indignation, or merely disagreement.
- Pertaining to the Sardinian language and those dialects of Catalan, spoken in the Balearic Islands and along the coast of Catalonia, that use definitive articles descended from the Latin ipse instead of the Latin ille.