The following words share an unusual characteristic.

CONQUERED
ALSO
"HEADS UP!' in golf
ATTACKS, as a dog
DEVOURED

HINTS:
1. Think of a synonym for each word.
2. Think of a homophone for each synonym.
3. The homophones are related.
4. It has to do with numbers.

Answers:

CONQUERED - WON -  ONE
ALSO - TOO - TWO
"HEADS UP!" in golf - FORE! - FOUR
ATTACKS, as a dog - SICS - SIX
DEVOURED - ATE - EIGHT