The most common and most likely answer to this crossword clue is the 9 letter word ACTIVATED
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The straight part
We know that "Switched on" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case switched on = activated.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 ACTIVATED mean?
ACTIVATED verb- To encourage development or induce increased activity; to stimulate.
- To put a device, mechanism (alarm etc.) or system into action or motion; to trigger, to actuate, to set off, to enable.
- To render more reactive; excite.
- To render a molecule reactive, active, or effective in performing its function.
- To render a substance radioactive.
- To hasten a chemical reaction, especially by heating.
- To remove the limitations of demoware by providing a license; to unlock.
- To aerate in order to aid decomposition of organic matter.
- To organize or create a military unit or station.
- To bring a player back after an injury.