1. One who sees the future

• Clairvoyant 

2. Can float

• Buoyant

3. Not a vowel

• Consonant

4. Flaky French roll

• Croissant

5. Accused in a trial

• Defendant

6. Makes you less stinky

• Deodorant

7. Unlocks stuffy nose

• Decongestant

8. Om om om

• Chant

9. The guy who hit me

• Assailant

10. The A in CA

• Accountant

11. Deadly tumour

• Malignant

12. Dr Who

• David Tennant

13. Absent from school

• Truant

14. Cop needs this to arrest you

• Warrant

15. Common to dogs and firemen

• Vigilant

16. What do you call a Newborn?

• Infant

17. Where Miss Universe is chosen

• Pageant

18. Something that is Way too expensive

• Extravagant