Related Clues:

• Like fluid in a battery
• Like vinegar or grapefruit juice
• Scathing
• Like lemon juice
• With a low pH
• Hard to endure
• Harsh-plus
• Like grapefruit juice
• Like apples and oranges
• Punishingly difficult
• Basic opposite
• Tart to the taste
• Like orange juice
• Like citrus juices
• Like lemonade