Related Clues:

• It's dropped for kicks
• Burn cause
• Hydrochloric or amino, e.g.
• Etcher's purchase, perhaps
• Part of DNA
• 91-Across, e.g.
• Etcher's purchase
• Low pH
• Sulfuric or hydrochloric follower
• Type of rain
• Corrosive chemical
• See 48 Across
• Dropped stuff
• Car battery component
• Cause of some bellyaching