King about to use website, perhaps, but will just observe silently (6)
I believe the answer is:
lurker
'use website perhaps but will just observe silently' is the definition.
I can't tell whether this definition defines the answer.
'king about to' is the wordplay.
'king' becomes 'K' (abbreviation for king in chess).
'about' indicates putting letters inside.
'to' becomes 'lurer' (I can't justify this - if you can you should give a lot more credence to this answer).
'k' going within 'lurer' is 'LURKER'.
Can you help me to learn more?
(Other definitions for lurker that I've seen before include "One waiting in ambush" , "One lying in ambush" , "Someone lying in wait" , "One remaining hidden" , "One lying hidden" .)