See a security device with a timing mechanism (5)
I believe the answer is:
clock
'a timing mechanism' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'see a security device' is the wordplay.
'see' becomes 'C' (the word for the letter, according to Chambers).
'a security device' becomes 'lock' (I've seen this before).
'c'+'lock'='CLOCK'
'with' is the link.
Can you help me to learn more?
(Other definitions for clock that I've seen before include "Watch" , "Hit" , "Striker" , "Timepiece" , "how to falsify car's mileage" .)