Related Clues:

• Basic education trio?
• Bear warning
• Angler's headache
• Rush-hour hassle
• Sound of mistrust
• Dog's snarl
• [I'm mad!]
• [I'm not happy about this]
• Sch. basics
• Basics of learning, briefly
• Canine threat
• Dull rumbling sound
• Dull, rumbling sound of an animal
• Emit low rumbling sounds
• How the sound of anger will increase to half a century