It's got a blinking lid on it! (3)
I believe the answer is:
eye
'it' is the definition.
The definition suggests a singular noun which matches the answer.
'it's got a blinking lid' is the wordplay.
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'got' says to put letters next to each other.
'a blinking lid' becomes 'ye' (I can't explain this - if you can you should give a lot more credence to this answer).
'e'+'ye'='EYE'
'on' is the link.
Can you help me to learn more?
(Other definitions for eye that I've seen before include "Light-detector" , "See 1" , "Aperture" , "20 [OBSERVE]" , "where the pupil is seated" .)