The most common and most likely answer to this crossword clue is the 5 letter word ROAMS
R
O
A
M
S
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The straight part
We know that "strays" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case strays = roams.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 ROAMS mean?
ROAMS verb- To wander or travel freely and with no specific destination.
- To use a network or service from different locations or devices.
- To transmit (resources) between different locations or devices, to allow comparable usage from any of them.
- To range or wander over.