1. Word List: retro-, an-, anti
backward, back, against, opposite

2. antacid
a substance that works against stomach acid

3. antibacterial
designed to fight against or kill bacteria

4. antidote
a remedy or cure; something works against a poison

5. antihistamine
a medicine that works against colds and allergies

6. antonym
a word that means the opposite of another word

7. retroactive
goes back to a prior time

8. retrofit
to go back and install something that was not available at the time of original manufacturing

9. retrospective
characterized by looking back at the pat and reflecting related to the past