Related Clues:

• See 43 Across
• Part of RNA
• Sulphuric or nitric
• Boric, e.g.
• Low-pH substance
• Mean and nasty
• Sour-tasting substance
• Carbolic and sulphuric ender
• Base neutralizer
• Scathing
• Target of milk of magnesia
• Slyly sarcastic
• It turns litmus paper red
• The ''A'' in DNA
• Insinuating, as a remark