Important notebook as a TV controller (6)
I believe the answer is:
keypad
'a tv controller' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'important notebook' is the wordplay.
'important' becomes 'key' (similar in meaning).
'notebook' becomes 'pad' (a notepad).
'key'+'pad'='KEYPAD'
'as' acts as a link.
Can you help me to learn more?
(Other definitions for keypad that I've seen before include "where one may have pressing needs" , "Device for data entry" , "Feature used to operate a portable electronic device" , "Small unit with push buttons" , "Mobile phone provides this" .)