She's bad-tempered and less than astute (5)
I believe the answer is:
shrew
'she's bad-tempered' is the definition.
I can't tell whether this defines the answer.
'less than astute' is the wordplay.
'less than' means to remove the last letter (not the full word).
'astute' becomes 'shrewd' (synonyms).
'shrewd' with its final letter taken off is 'SHREW'.
'and' is the link.
Can you help me to learn more?
(Other definitions for shrew that I've seen before include "Woman who's assertive" , "Mouselike insectivore" , "Petruchio tamed one" , "Shakespeare: 'The Taming of the ....'" , "Insectivore - Katharina" .)