craven
Cowardly in a shameful way, especially when courage is needed.
Craven means cowardly in a shameful, contemptible way. It describes someone who lacks courage when courage really matters, especially someone who abandons their principles or betrays others to save themselves.
A craven person lets their fear make them do dishonorable things. While anyone might feel afraid when facing something dangerous or difficult, a craven person puts their own safety above everything else, even at the cost of hurting others or breaking their word. If a bully's friend knows the bullying is wrong but joins in anyway because they're afraid of becoming the next target, that's craven behavior.
The word carries strong disapproval. Calling someone craven suggests they've failed a basic test of character. In stories throughout history, craven characters are often shown as villains or figures of contempt: the knight who flees from battle, the politician who betrays their supporters to avoid consequences, the person who blames an innocent friend to escape punishment.
Being afraid isn't craven. What makes someone craven is letting that fear turn them into someone who can't be trusted or respected. It's the difference between feeling scared but standing firm, and letting fear control your choices in ways that harm others or yourself.