Powerful petty officer gets mobile home (6)
I believe the answer is:
potent
'powerful' is the definition.
(I know that powerful can be written as potent)
'petty officer gets mobile home' is the wordplay.
'petty officer' becomes 'po' (naval abbreviation).
'gets' says to put letters next to each other.
'mobile home' becomes 'tent' (I've seen this in another clue).
'po'+'tent'='POTENT'
(Other definitions for potent that I've seen before include "Powerful or effective" , "Maybe overpowering" , "Strong or concentrated, like some drink" , "Top Ten (anag.)" , "Powerful, influential" .)