Though most sensible, is in a terrible stew (6)
I believe the answer is:
wisest
'though most sensible' is the definition.
I can't tell whether this defines the answer.
'is in a terrible stew' is the wordplay.
'in' indicates putting letters inside.
'a terrible' indicates anagramming the letters.
'stew' anagrammed gives 'west'.
'is' going into 'west' is 'WISEST'.
Can you help me to learn more?
(Other definitions for wisest that I've seen before include "Most sage and sagacious" , "Showing the most knowledge and good judgment" , "Most astute" , "Most sage or experienced" , "Most judicious" .)