Frowned when a beastly female entered the vehicle (7)

I believe the answer is:
scowled
'frowned' is the definition.
(scowling is a kind of frowning)
'a beastly female entered the vehicle' is the wordplay.
'a beastly female' becomes 'cow' (I've seen this before. I am not sure about the 'beastly' bit.).
'entered' is an insertion indicator.
'the vehicle' becomes 'sled' (sled is a kind of vehicle).
'cow' going within 'sled' is 'SCOWLED'.
'when' acts as a link.
Can you help me to learn more?
(Other definitions for scowled that I've seen before include "Pulled a face" , "Looked gloomy" .)
