The most common and most likely answer to this crossword clue is the 8 letter word LABOURED
I've seen this crossword clue in The Daily Telegraph
L
A
B
O
U
R
E
D
Buddy explains!
The straight part
We know that "Strained" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case strained = laboured.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 LABOURED mean?
LABOURED verb- To toil, to work.
- To belabour, to emphasise or expand upon (a point in a debate, etc).
- To be oppressed with difficulties or disease; to do one's work under conditions which make it especially hard or wearisome; to move slowly, as against opposition, or under a burden.
- To suffer the pangs of childbirth.
- To pitch or roll heavily, as a ship in a turbulent sea.
- Expressive of strenuous effort.
- Of writing or speech or similar, stilted or not natural due to too much effort being used in the production.