Take a firm stand at home and start to shave first (6)
I believe the answer is:
insist
'take a firm stand' is the definition.
('insist' can be a synonym of 'take a firm stand')
'home and start to shave first' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'and' means one lot of letters go next to another.
'start to' suggests taking the first letters.
'first' becomes 'ist'.
The first letter of 'shave' is 's'.
'in'+'s'+'ist'='INSIST'
'at' acts as a link.
(Other definitions for insist that I've seen before include "Urge" , "Maintain persistently" , "Declare or demand emphatically" , "Assert firmly" , "Demand determinedly" .)