Browser regularly kidded, boring thinker (4,4)

'thinker' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.

'browser regularly kidded boring' is the wordplay.
'browser' becomes 'muser' (I can't justify this - if you can you should believe this answer much more).
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'boring' is an insertion indicator (to bore something can mean to drill into it).
The alternating letters of 'kidded' are 'kde'.
'muser' going around 'kde' is 'MUSK-DEER'.

Can you help me to learn more?