What is the definition of insecure and how should it be applied during an MOT test?

...readily be moved on the handlebar. Also a headlamp would be deemed insecure if it was free to move and so alter the aim position, while a rear position lamp...
...readily be moved on the handlebar. Also a headlamp would be deemed insecure if it was free to move and so alter the aim position, while a rear position lamp...