It's easy for one to get fifty in front (6)
I believe the answer is:
facile
'it's easy' is the definition.
(synonyms)
'one to get fifty in front' is the wordplay.
'one' becomes 'I' (Roman numeral).
'to get' says to put letters next to each other.
'fifty' becomes 'L' (Roman numeral).
'in' indicates putting letters inside.
'front' becomes 'face' (synonyms).
'i'+'l'='il'
'il' going into 'face' is 'FACILE'.
'for' is the link.
(Other definitions for facile that I've seen before include "Easily achieved but of little value" , "Too easily achieved, glib" , "Easy to accomplish" , "Superficial or too easily achieved" , "Smooth" .)