Conscientious way a top man accompanies father home (11)
I believe the answer is:
painstaking
'conscientious' is the definition.
(synonyms)
'way a top man accompanies father home' is the wordplay.
'way' becomes 'st' (abbreviation for street).
'top man' becomes 'king' (male ruler).
'accompanies' is a charade indicator (letters next to each other).
'father' becomes 'pa' (pa can mean dad or father).
'home' becomes 'in' ('he's home' can mean 'he's in').
'st'+'a'+'king'='staking'
'pa'+'in'='pain'
'staking' put 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" .)