The most common and most likely answer to this crossword clue is the 7 letter word ORDEALS
I've seen this crossword clue in The Daily Telegraph
O
R
D
E
A
L
S
More clues leading to the result ORDEALS
Buddy explains!

The straight part
We know that "Trials" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case trials = ordeals.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 ORDEALS mean?
ORDEALS noun- A painful or trying experience.
- A trial in which the accused was subjected to a dangerous test (such as ducking in water), divine authority deciding the guilt of the accused.
- The poisonous ordeal bean or Calabar bean