Some man I certified gets better (5)
I believe the answer is:
nicer
'better' is the definition.
(I've seen this before)
'some man i certified' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'NICER' can be found hidden inside 'man i certified'.
'gets' is the link.
(Other definitions for nicer that I've seen before include "relatively pleasant" , "Even more 7 down!" , "it's more appealing" , "more accurate" , "harder to please" .)