The most common and most likely answer to this crossword clue is the 10 letter word PAINKILLER
I've seen this crossword clue in The Times
P
A
I
N
K
I
L
L
E
R
More clues leading to the result PAINKILLER
- A shade less healthy after swallowing a tablet?
- Rose more sick swallowing a tablet?
- It lessens suffering of old man held by assassin
- Dad, not so well, swallowing liquid analgesic
- Analgesic for father taking half 24 and getting less well
- Father Mark’s unfortunate – Casualty is anodyne
- Aspirin maybe needed by father with trendy person who takes life seriously?
- Dad with bad hesitancy in speech must swallow liquid medicine
- One shouldn’t feel hurt when it’s used
- Assassin after father at home gets an analgesic
Buddy explains!

The straight part
We know that "tablet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tablet = painkiller.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 PAINKILLER mean?
PAINKILLER noun- A drug that numbs the pain in the body.