Become left behind and react angrily (5)
I believe the answer is:
growl
'react angrily' is the definition.
I can't judge whether this definition defines the answer.
'become left behind' is the wordplay.
'become' becomes 'grow' (I've seen this in another clue).
'left' becomes 'L' (common abbreviation).
'behind' is a charade indicator (letters next to each other).
'grow'+'l'='GROWL'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for growl that I've seen before include "Surly grumble" , "bare teeth" , "warn of attack" , "(Make a) menacing sound" , "Hostile murmur" .)