What do the following words have in common?

 

1. ACT

2. ADD

3. DIG

4. HUNT

5. IMP

6. RED

7. TEMPT

8. WAIT

HINT:

The same four letters can be added to each word.

The letters RESS can be added at the end of each word to give a new one:

 

1. ACTRESS

2. ADDRESS

3. DIGRESS

4. HUNTRESS

5. IMPRESS

6. REDRESS

7. TEMPTRESS

8. WAITRESS