growl 
(groul)
n.1. The low, guttural, menacing sound made by an animal: the growl of a dog.
2. A gruff surly utterance: The desk officer answered my greeting with a growl.
v. growled, growl·ing, growls
v.intr.1. To emit a low guttural sound or utterance.
2. To speak in an angry or surly manner.
v.tr. To utter by growling: growled the orders.
[Middle English groule, grollen, to rumble, growl, probably from Old French grouler, of Germanic origin.]
growly adj.