Serious listener at home (7)
I believe the answer is:
earnest
'serious' is the definition.
(similar in meaning)
'listener at home' is the wordplay.
'listener' becomes 'ear' (body part which hears or listens).
'at' is a charade indicator (letters next to each other).
'home' becomes 'nest' (a bird's home).
'ear'+'nest'='EARNEST'
(Other definitions for earnest that I've seen before include "Something of value to bind a contract" , "Serious; pledge" , "Serious - advance" , "Oscar Wilde play 'The Importance of Being . . . . . . .'" , "See 1" .)