Urges one to become Liberal? (8)
I believe the answer is:
generous
'liberal?' is the definition.
(similar in meaning)
'urges one to become' is the wordplay.
'to become' indicates anagramming the letters.
'urges'+'one'='urgesone'
'urgesone' anagrammed gives 'GENEROUS'.
(Other definitions for generous that I've seen before include "Kind towards others" , "Free" , "Lavish" , "Willing to give unstintingly" , "Beneficent, perhaps to a fault" .)