Scientist is too glib, sadly (9)
I believe the answer is:
biologist
'scientist' is the definition.
(I know that biologist is a type of scientist)
'is too glib sadly' is the wordplay.
'sadly' indicates anagramming the letters.
'is'+'too'+'glib'='istooglib'
'istooglib' is an anagram of 'BIOLOGIST'.
(Other definitions for biologist that I've seen before include "scientist" , "A studier of living organisms" , "e.g. Darwin" , "Expert on living organisms" .)