Yowl! I am upset you trod on my paw! (5)
I believe the answer is:
miaow
'yowl' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for miaow that I've seen before include "What the cat says" , "Cry of a cat" , "How Persian might go" , "Sound like a cat" , "Beastly remark" .)