Plough etc, maintaining earth for peers (6)
I believe the answer is:
stares
'peers' is the definition.
'plough etc maintaining earth' is the wordplay.
'plough etc' becomes 'stars' (the Plough is a constellation).
'maintaining' indicates putting letters inside.
'earth' becomes 'e'.
'stars' enclosing 'e' is 'STARES'.
'for' acts as a link.
(Other definitions for stares that I've seen before include "Assert with long looks" , "Looks lengthily at" , "Looks fixedly" , "Looks hard" , "Long gazes" .)