Conscientious way a top man accompanies father home (11)
I believe the answer is:
painstaking
'conscientious' is the definition.
(I know that conscientious can be written as painstaking)
'way a top man accompanies father home' is the wordplay.
'way' becomes 'st' (abbreviation for street).
'top man' becomes 'king' (male ruler).
'accompanies' says to put letters next to each other.
'father' becomes 'pa' (pa can mean dad or father).
'home' becomes 'in' (to be in is to be (at) home).
'st'+'a'+'king'='staking'
'pa'+'in'='pain'
'staking' after 'pain' is 'PAINSTAKING'.
(Other definitions for painstaking that I've seen before include "Diligent, scrupulous" , "Extremely careful" , "Laboriously careful" , "using great care" , "Assiduous, thorough" .)