cowardly
adjective /ˈkaʊədli/
  /ˈkaʊərdli/
 (disapproving)- not brave; not having the courage to do things that other people do not think are especially difficult
- the actions of a weak and cowardly man
 
 - (of an action) carried out against a person who is unable to fight back
- a cowardly attack on a defenceless man
 
 opposite brave